Use ozone for x11

Switch to use ozone also for x11/glx. This way we have a
more elegant approach to hook in our gl surface classes
and we use ozone for all linux qpa backends. Moreover,
we have now also more fine grain control to reimplement
gl surface handling logic.

This also aims to fix currently broken wayland backend,
but instead of patching the broken x11 calls, we simply reuse
ozone which does not use x11 for ozone egl.

Add webengine-x11 check to handle ozone glx plugin compilation.

For ozone egl backend reimplement missing functions.

Task-number: QTBUG-65682
Task-number: QTBUG-51631
Change-Id: I8b45c6f4d09a1c703efb12b6452d78ab385371ab
Reviewed-by: Jüri Valdmann <juri.valdmann@qt.io>

21 files changed, 381 insertions, 233 deletions

diff --git a/mkspecs/features/functions.prf b/mkspecs/features/functions.prf
index 8564bad8a..ac84ad321 100644
--- a/mkspecs/features/functions.prf
+++ b/mkspecs/features/functions.prf
@@ -77,10 +77,7 @@ defineReplace(gnPath) {
 }
 
 defineReplace(gnArgs) {
-    linux {
-        qtConfig(webengine-embedded-build): include($$QTWEBENGINE_ROOT/src/core/config/embedded_linux.pri)
-        else: include($$QTWEBENGINE_ROOT/src/core/config/desktop_linux.pri)
-    }
+    linux: include($$QTWEBENGINE_ROOT/src/core/config/linux.pri)
     macos: include($$QTWEBENGINE_ROOT/src/core/config/mac_osx.pri)
     win32: include($$QTWEBENGINE_ROOT/src/core/config/windows.pri)
     isEmpty(gn_args): error(No gn_args found please make sure you have valid configuration.)
diff --git a/src/core/chromium_overrides.cpp b/src/core/chromium_overrides.cpp
index cb5674c37..3aa554eb6 100644
--- a/src/core/chromium_overrides.cpp
+++ b/src/core/chromium_overrides.cpp
@@ -59,10 +59,6 @@
 #include <QFontDatabase>
 #include <QStringList>
 
-#if defined(USE_X11)
-#include "ui/gfx/x/x11_types.h"
-#endif
-
 #if defined(USE_AURA) && !defined(USE_OZONE)
 #include "ui/base/dragdrop/os_exchange_data.h"
 #include "ui/base/dragdrop/os_exchange_data_provider_aura.h"
@@ -95,27 +91,6 @@ void GetScreenInfoFromNativeWindow(QWindow* window, content::ScreenInfo* results
 
 } // namespace QtWebEngineCore
 
-#if defined(USE_X11)
-XDisplay* GetQtXDisplay()
-{
-    return static_cast<XDisplay*>(GLContextHelper::getXDisplay());
-}
-
-namespace ui {
-class DummyPlatformEventSource : public PlatformEventSource
-{
-public:
-    DummyPlatformEventSource() {
-        DeviceDataManager::CreateInstance();
-    }
-};
-
-std::unique_ptr<PlatformEventSource> PlatformEventSource::CreateDefault() {
-  return std::make_unique<DummyPlatformEventSource>();
-}
-} // namespace ui
-#endif // defined(USE_X11)
-
 namespace content {
 class WebContentsImpl;
 class WebContentsView;
diff --git a/src/core/config/desktop_linux.pri b/src/core/config/desktop_linux.pri
deleted file mode 100644
index 70f1cf81e..000000000
--- a/src/core/config/desktop_linux.pri
+++ /dev/null
@@ -1,8 +0,0 @@
-include(linux.pri)
-
-gn_args += \
-    use_sysroot=false \
-    enable_session_service=false \
-    toolkit_views=false
-
-!use_gold_linker: gn_args += use_gold=false
diff --git a/src/core/config/embedded_linux.pri b/src/core/config/embedded_linux.pri
deleted file mode 100644
index 8d9f09deb..000000000
--- a/src/core/config/embedded_linux.pri
+++ /dev/null
@@ -1,13 +0,0 @@
-include(linux.pri)
-
-gn_args += \
-    is_desktop_linux=false \
-    use_gold=false \
-    use_ozone=true \
-    use_sysroot=false \
-    enable_session_service=false \
-    ozone_auto_platforms=false \
-    ozone_platform_headless=true \
-    ozone_platform_external=true \
-    ozone_platform=\"qt\" \
-    toolkit_views=false
diff --git a/src/core/config/linux.pri b/src/core/config/linux.pri
index 7299819a6..f06679a3b 100644
--- a/src/core/config/linux.pri
+++ b/src/core/config/linux.pri
@@ -8,7 +8,26 @@ gn_args += \
     use_kerberos=false \
     linux_use_bundled_binutils=false \
     use_udev=true \
-    use_bundled_fontconfig=false
+    use_bundled_fontconfig=false \
+    use_sysroot=false \
+    enable_session_service=false \
+    toolkit_views=false \
+    use_ozone=true \
+    ozone_auto_platforms=false \
+    ozone_platform_headless=true \
+    ozone_platform_external=true \
+    ozone_platform=\"qt\"
+
+qtConfig(webengine-embedded-build) {
+    gn_args += is_desktop_linux=false
+    gn_args += use_gold=false
+} else {
+    !use_gold_linker: gn_args += use_gold=false
+}
+
+qtConfig(webengine-system-x11) {
+   gn_args += ozone_platform_x11=true
+}
 
 clang {
     clang_full_path = $$which($${QMAKE_CXX})
diff --git a/src/core/configure.json b/src/core/configure.json
index 51dd561e4..789da3351 100644
--- a/src/core/configure.json
+++ b/src/core/configure.json
@@ -208,9 +208,14 @@
             "sources": [
                 { "type": "pkgConfig", "args": "freetype2 >= 2.4.2" }
             ]
+        },
+        "webengine-x11" : {
+            "label" : "x11",
+            "sources": [
+                { "type": "pkgConfig", "args": "x11" }
+            ]
         }
     },
-
     "tests" : {
         "webengine-alsa": {
             "label": "alsa",
@@ -604,6 +609,11 @@
             "condition": "config.unix && features.system-freetype && libs.webengine-freetype",
             "output": [ "privateFeature" ]
         },
+        "webengine-system-x11" : {
+            "label": "x11",
+            "condition": "config.unix && libs.webengine-x11",
+            "output": [ "privateFeature" ]
+        },
         "webengine-sanitizer" : {
             "label": "Sanitizer",
             "autoDetect": "config.sanitizer && tests.webengine-sanitizer",
@@ -732,7 +742,8 @@
                         "webengine-system-png",
                         "webengine-system-jpeg",
                         "webengine-system-harfbuzz",
-                        "webengine-system-freetype"
+                        "webengine-system-freetype",
+                        "webengine-system-x11"
                     ]
                 },
                 {
diff --git a/src/core/core_chromium.pri b/src/core/core_chromium.pri
index 7ed489f14..a2c22c5d2 100644
--- a/src/core/core_chromium.pri
+++ b/src/core/core_chromium.pri
@@ -84,7 +84,6 @@ SOURCES = \
         net/webui_controller_factory_qt.cpp \
         ozone/gl_ozone_egl_qt.cpp \
         ozone/gl_surface_egl_qt.cpp \
-        ozone/gl_surface_glx_qt.cpp \
         ozone/gl_surface_wgl_qt.cpp \
         ozone/ozone_platform_qt.cpp \
         ozone/platform_window_qt.cpp \
@@ -174,7 +173,6 @@ HEADERS = \
         net/webui_controller_factory_qt.h \
         ozone/gl_ozone_egl_qt.h \
         ozone/gl_surface_egl_qt.h \
-        ozone/gl_surface_glx_qt.h \
         ozone/gl_surface_wgl_qt.h \
         ozone/ozone_platform_qt.h \
         ozone/platform_window_qt.h \
@@ -219,6 +217,14 @@ HEADERS = \
         web_engine_settings.h \
         web_event_factory.h
 
+
+qtConfig(webengine-system-x11) {
+    HEADERS += ozone/gl_ozone_glx_qt.h \
+               ozone/gl_surface_glx_qt.h
+    SOURCES += ozone/gl_surface_glx_qt.cpp \
+               ozone/gl_ozone_glx_qt.cpp
+}
+
 qtConfig(webengine-pepper-plugins) {
 
     SOURCES += \
diff --git a/src/core/delegated_frame_node.cpp b/src/core/delegated_frame_node.cpp
index 5b0983924..5257602cf 100644
--- a/src/core/delegated_frame_node.cpp
+++ b/src/core/delegated_frame_node.cpp
@@ -140,7 +140,7 @@ private:
     QSize m_textureSize;
     bool m_hasAlpha;
     GLenum m_target;
-#if defined(USE_X11)
+#if defined(USE_OZONE)
     bool m_ownsTexture;
 #endif
 #ifdef Q_OS_QNX
@@ -571,7 +571,7 @@ MailboxTexture::MailboxTexture(const gpu::MailboxHolder &mailboxHolder, const QS
     , m_textureSize(textureSize)
     , m_hasAlpha(false)
     , m_target(GL_TEXTURE_2D)
-#if defined(USE_X11)
+#if defined(USE_OZONE)
     , m_ownsTexture(false)
 #endif
 {
@@ -586,7 +586,7 @@ MailboxTexture::MailboxTexture(const gpu::MailboxHolder &mailboxHolder, const QS
 
 MailboxTexture::~MailboxTexture()
 {
-#if defined(USE_X11)
+#if defined(USE_OZONE)
    // This is rare case, where context is not shared
    // we created extra texture in current context, so
    // delete it now
@@ -708,12 +708,12 @@ RectClipNode::RectClipNode(const QRectF &rect)
 
 DelegatedFrameNode::DelegatedFrameNode()
     : m_numPendingSyncPoints(0)
-#if defined(USE_X11) && !defined(QT_NO_OPENGL)
+#if defined(USE_OZONE) && !defined(QT_NO_OPENGL)
     , m_contextShared(true)
 #endif
 {
     setFlag(UsePreprocess);
-#if defined(USE_X11) && !defined(QT_NO_OPENGL)
+#if defined(USE_OZONE) && !defined(QT_NO_OPENGL)
     QOpenGLContext *currentContext = QOpenGLContext::currentContext() ;
     QOpenGLContext *sharedContext = qt_gl_global_share_context();
     if (currentContext && sharedContext && !QOpenGLContext::areSharing(currentContext, sharedContext)) {
@@ -1294,7 +1294,7 @@ void DelegatedFrameNode::fetchAndSyncMailboxes(QList<MailboxTexture *> &mailboxe
         deleteChromiumSync(&sync);
     }
 
-#if defined(USE_X11)
+#if defined(USE_OZONE)
     // Workaround when context is not shared QTBUG-48969
     // Make slow copy between two contexts.
     if (!m_contextShared) {
diff --git a/src/core/delegated_frame_node.h b/src/core/delegated_frame_node.h
index 5d967841d..e37ad08a3 100644
--- a/src/core/delegated_frame_node.h
+++ b/src/core/delegated_frame_node.h
@@ -143,7 +143,7 @@ private:
     QWaitCondition m_mailboxesFetchedWaitCond;
     QMutex m_mutex;
     QList<gl::TransferableFence> m_textureFences;
-#if defined(USE_X11)
+#if defined(USE_OZONE)
     bool m_contextShared;
     QScopedPointer<QOffscreenSurface> m_offsurface;
 #endif
diff --git a/src/core/gl_context_qt.cpp b/src/core/gl_context_qt.cpp
index 954917094..ad78b7d2b 100644
--- a/src/core/gl_context_qt.cpp
+++ b/src/core/gl_context_qt.cpp
@@ -46,10 +46,6 @@
 #include "ui/gl/gl_context_egl.h"
 #include "ui/gl/gl_implementation.h"
 
-#if defined(USE_X11)
-#include <X11/Xlib.h>
-#endif
-
 #if defined(OS_WIN)
 #include "ui/gl/gl_context_wgl.h"
 #endif
@@ -128,15 +124,8 @@ void* GLContextHelper::getEGLDisplay()
 
 void* GLContextHelper::getXDisplay()
 {
-    void *display = qApp->platformNativeInterface()->nativeResourceForScreen(QByteArrayLiteral("display"), qApp->primaryScreen());
-#if defined(USE_X11)
-    if (!display) {
-        // XLib isn't available or has not been initialized, which is a decision we wish to
-        // support, for example for the GPU process.
-        display = XOpenDisplay(NULL);
-    }
-#endif
-    return display;
+    return qApp->platformNativeInterface()->nativeResourceForScreen(
+                QByteArrayLiteral("display"), qApp->primaryScreen());
 }
 
 void* GLContextHelper::getNativeDisplay()
@@ -168,17 +157,14 @@ QFunctionPointer GLContextHelper::getEglGetProcAddress()
 
 QT_END_NAMESPACE
 
-#if defined(USE_OZONE) || defined(OS_WIN)
-
+#if defined(OS_WIN)
 namespace gl {
-
 namespace init {
 
 scoped_refptr<GLContext> CreateGLContext(GLShareGroup* share_group,
                                          GLSurface* compatible_surface,
                                          const GLContextAttribs& attribs)
 {
-#if defined(OS_WIN)
     scoped_refptr<GLContext> context;
     if (GetGLImplementation() == kGLImplementationDesktopGL) {
         context = new GLContextWGL(share_group);
@@ -188,18 +174,14 @@ scoped_refptr<GLContext> CreateGLContext(GLShareGroup* share_group,
     } else {
         context = new GLContextEGL(share_group);
     }
-#else
-    scoped_refptr<GLContext> context = new GLContextEGL(share_group);
-#endif
 
     if (!GLContextHelper::initializeContext(context.get(), compatible_surface, attribs))
-        return NULL;
+        return nullptr;
 
     return context;
 }
 
 }  // namespace init
-
 }  // namespace gl
 
-#endif // defined(USE_OZONE) || defined(OS_WIN)
+#endif // defined(OS_WIN)
diff --git a/src/core/gl_surface_qt.cpp b/src/core/gl_surface_qt.cpp
index 4d38d7c25..7cde289ae 100644
--- a/src/core/gl_surface_qt.cpp
+++ b/src/core/gl_surface_qt.cpp
@@ -68,13 +68,6 @@
 #include "ui/gl/vsync_provider_win.h"
 #endif
 
-#if defined(USE_X11)
-#include "ozone/gl_surface_glx_qt.h"
-#include "ui/gl/gl_glx_api_implementation.h"
-#include <dlfcn.h>
-
-#endif
-
 #include "ozone/gl_surface_egl_qt.h"
 #include "ui/gl/gl_egl_api_implementation.h"
 
@@ -142,13 +135,11 @@ void* GLSurfaceQt::GetConfig()
     return g_config;
 }
 
+#if defined(OS_WIN)
 namespace init {
-
 bool InitializeGLOneOffPlatform()
 {
-#if defined(OS_WIN)
     VSyncProviderWin::InitializeOneOff();
-#endif
 
     if (GetGLImplementation() == kGLImplementationOSMesaGL)
         return false;
@@ -157,12 +148,8 @@ bool InitializeGLOneOffPlatform()
         return GLSurfaceEGLQt::InitializeOneOff();
 
     if (GetGLImplementation() == kGLImplementationDesktopGL) {
-#if defined(OS_WIN)
         return GLSurfaceWGLQt::InitializeOneOff();
-#elif defined(USE_X11)
-        if (GLSurfaceGLXQt::InitializeOneOff())
-            return true;
-#endif
+
         // Fallback to trying EGL with desktop GL.
         if (GLSurfaceEGLQt::InitializeOneOff()) {
             g_initializedEGL = true;
@@ -173,87 +160,6 @@ bool InitializeGLOneOffPlatform()
     return false;
 }
 
-#if defined(USE_X11)
-// FIXME: This should be removed when we switch to OZONE only
-bool InitializeStaticGLBindings(GLImplementation implementation) {
-  // Prevent reinitialization with a different implementation. Once the gpu
-  // unit tests have initialized with kGLImplementationMock, we don't want to
-  // later switch to another GL implementation.
-  DCHECK_EQ(kGLImplementationNone, GetGLImplementation());
-  base::ThreadRestrictions::ScopedAllowIO allow_io;
-
-  switch (implementation) {
-    case kGLImplementationOSMesaGL:
-      return false;
-    case kGLImplementationDesktopGL: {
-      base::NativeLibrary library = dlopen(NULL, RTLD_LAZY);
-      if (!library) {
-          LOG(ERROR) << "Failed to obtain glx handle" << dlerror();
-          return false;
-      }
-
-      GLGetProcAddressProc get_proc_address =
-          reinterpret_cast<GLGetProcAddressProc>(
-              base::GetFunctionPointerFromNativeLibrary(library,
-                                                        "glXGetProcAddress"));
-      if (!get_proc_address) {
-          QFunctionPointer address = GLContextHelper::getGlXGetProcAddress();
-          get_proc_address = reinterpret_cast<gl::GLGetProcAddressProc>(address);
-      }
-      if (!get_proc_address) {
-          LOG(ERROR) << "glxGetProcAddress not found.";
-          base::UnloadNativeLibrary(library);
-          return false;
-      }
-
-      SetGLGetProcAddressProc(get_proc_address);
-      AddGLNativeLibrary(library);
-      SetGLImplementation(kGLImplementationDesktopGL);
-
-      InitializeStaticGLBindingsGL();
-      InitializeStaticGLBindingsGLX();
-      return true;
-    }
-    case kGLImplementationSwiftShaderGL:
-    case kGLImplementationEGLGLES2: {
-       base::NativeLibrary library = dlopen(NULL, RTLD_LAZY);
-       if (!library) {
-           LOG(ERROR) << "Failed to obtain egl handle" << dlerror();
-           return false;
-       }
-
-       GLGetProcAddressProc get_proc_address =
-          reinterpret_cast<GLGetProcAddressProc>(
-              base::GetFunctionPointerFromNativeLibrary(library,
-                                                        "eglGetProcAddress"));
-      if (!get_proc_address) {
-          QFunctionPointer address = GLContextHelper::getEglGetProcAddress();
-          get_proc_address = reinterpret_cast<gl::GLGetProcAddressProc>(address);
-      }
-      if (!get_proc_address) {
-        LOG(ERROR) << "eglGetProcAddress not found.";
-        base::UnloadNativeLibrary(library);
-        return false;
-      }
-
-      SetGLGetProcAddressProc(get_proc_address);
-      AddGLNativeLibrary(library);
-      SetGLImplementation(kGLImplementationEGLGLES2);
-
-      InitializeStaticGLBindingsGL();
-      InitializeStaticGLBindingsEGL();
-      return true;
-    }
-    case kGLImplementationMockGL:
-    case kGLImplementationStubGL:
-      return false;
-    default:
-      NOTREACHED();
-  }
-  return false;
-}
-#endif
-
 bool usingSoftwareDynamicGL()
 {
     return QtWebEngineCore::usingSoftwareDynamicGL();
@@ -266,19 +172,10 @@ CreateOffscreenGLSurfaceWithFormat(const gfx::Size& size, GLSurfaceFormat format
     switch (GetGLImplementation()) {
     case kGLImplementationDesktopGLCoreProfile:
     case kGLImplementationDesktopGL: {
-#if defined(OS_WIN)
         surface = new GLSurfaceWGLQt(size);
         if (surface->Initialize(format))
             return surface;
         break;
-#elif defined(USE_X11)
-        if (!g_initializedEGL) {
-            surface = new GLSurfaceGLXQt(size);
-            if (surface->Initialize(format))
-                return surface;
-        }
-        Q_FALLTHROUGH();
-#endif
     }
     case kGLImplementationEGLGLES2: {
         surface = new GLSurfaceEGLQt(size);
@@ -313,8 +210,10 @@ CreateViewGLSurface(gfx::AcceleratedWidget window)
 }
 
 } // namespace init
-}  // namespace gl
+#endif  // defined(OS_WIN)
+} // namespace gl
 
+#if defined(OS_WIN)
 namespace gpu {
 class GpuCommandBufferStub;
 class GpuChannelManager;
@@ -325,11 +224,10 @@ scoped_refptr<gl::GLSurface> ImageTransportSurface::CreateNativeSurface(base::We
     return scoped_refptr<gl::GLSurface>();
 }
 
-#if defined(OS_WIN)
 bool DirectCompositionSurfaceWin::IsHDRSupported()
-{   return false; }
-#endif
-
+{
+    return false;
+}
 } // namespace gpu
-
+#endif
 #endif // !defined(OS_MACOSX)
diff --git a/src/core/ozone/gl_ozone_egl_qt.cpp b/src/core/ozone/gl_ozone_egl_qt.cpp
index a9b3da5e2..bc7b2b756 100644
--- a/src/core/ozone/gl_ozone_egl_qt.cpp
+++ b/src/core/ozone/gl_ozone_egl_qt.cpp
@@ -38,11 +38,13 @@
 ****************************************************************************/
 
 #if defined(USE_OZONE)
-
+#include "gl_ozone_egl_qt.h"
+#include "gl_context_qt.h"
+#include "gl_surface_egl_qt.h"
 #include "base/files/file_path.h"
 #include "base/native_library.h"
 #include "gl_context_qt.h"
-#include "ozone/gl_ozone_egl_qt.h"
+#include "gl_ozone_egl_qt.h"
 #include "ui/gl/gl_context_egl.h"
 #include "ui/gl/gl_implementation.h"
 #include "ui/gl/gl_surface.h"
@@ -55,10 +57,12 @@
 
 #ifndef QT_NO_OPENGL
 #include <QOpenGLContext>
+QT_BEGIN_NAMESPACE
 Q_GUI_EXPORT QOpenGLContext *qt_gl_global_share_context();
+QT_END_NAMESPACE
 #endif
 
-namespace QtWebEngineCore {
+namespace ui {
 
 base::NativeLibrary LoadLibrary(const base::FilePath& filename) {
     base::NativeLibraryLoadError error;
@@ -103,6 +107,39 @@ bool GLOzoneEGLQt::LoadGLES2Bindings(gl::GLImplementation /*implementation*/)
     return true;
 }
 
+bool GLOzoneEGLQt::InitializeGLOneOffPlatform()
+{
+    if (!gl::GLSurfaceEGLQt::InitializeOneOff()) {
+        LOG(ERROR) << "GLOzoneEGLQt::InitializeOneOff failed.";
+        return false;
+    }
+    return true;
+}
+
+bool GLOzoneEGLQt::InitializeExtensionSettingsOneOffPlatform()
+{
+    return gl::GLSurfaceEGLQt::InitializeExtensionSettingsOneOff();
+}
+
+scoped_refptr<gl::GLSurface> GLOzoneEGLQt::CreateViewGLSurface(gfx::AcceleratedWidget window)
+{
+    return nullptr;
+}
+
+scoped_refptr<gl::GLSurface> GLOzoneEGLQt::CreateOffscreenGLSurface(const gfx::Size &size)
+{
+    scoped_refptr<gl::GLSurface> surface = new gl::GLSurfaceEGLQt(size);
+    if (surface->Initialize(gl::GLSurfaceFormat()))
+        return surface;
+
+    surface = new gl::GLSurfacelessQtEGL(size);
+    if (surface->Initialize(gl::GLSurfaceFormat()))
+        return surface;
+
+    LOG(WARNING) << "Failed to create offscreen GL surface";
+    return nullptr;
+}
+
 intptr_t GLOzoneEGLQt::GetNativeDisplay()
 {
     static void *display = GLContextHelper::getNativeDisplay();
@@ -113,6 +150,6 @@ intptr_t GLOzoneEGLQt::GetNativeDisplay()
     return reinterpret_cast<intptr_t>(EGL_DEFAULT_DISPLAY);
 }
 
-} // namespace QtWebEngineCore
+} // namespace ui
 
 #endif // defined(USE_OZONE)
diff --git a/src/core/ozone/gl_ozone_egl_qt.h b/src/core/ozone/gl_ozone_egl_qt.h
index fc609c51c..c24d03a81 100644
--- a/src/core/ozone/gl_ozone_egl_qt.h
+++ b/src/core/ozone/gl_ozone_egl_qt.h
@@ -44,18 +44,16 @@
 
 #include "ui/ozone/common/gl_ozone_egl.h"
 
-namespace QtWebEngineCore {
+namespace ui {
 
-class GLOzoneEGLQt : public ui::GLOzoneEGL {
+class GLOzoneEGLQt : public GLOzoneEGL {
 public:
-    scoped_refptr<gl::GLSurface> CreateViewGLSurface(gfx::AcceleratedWidget /*window*/) override
-    {
-        return nullptr;
-    }
-    scoped_refptr<gl::GLSurface> CreateOffscreenGLSurface(const gfx::Size& /*size*/) override
-    {
-        return nullptr;
-    }
+    bool InitializeGLOneOffPlatform() override;
+    bool InitializeExtensionSettingsOneOffPlatform() override;
+    scoped_refptr<gl::GLSurface> CreateViewGLSurface(
+            gfx::AcceleratedWidget window) override;
+    scoped_refptr<gl::GLSurface> CreateOffscreenGLSurface(
+            const gfx::Size& size) override;
 
 protected:
     // Returns native platform display handle. This is used to obtain the EGL
@@ -66,7 +64,7 @@ protected:
     bool LoadGLES2Bindings(gl::GLImplementation implementation) override;
 };
 
-} // namespace QtWebEngineCore
+} // namespace ui
 
 #endif // defined(USE_OZONE)
 
diff --git a/src/core/ozone/gl_ozone_glx_qt.cpp b/src/core/ozone/gl_ozone_glx_qt.cpp
new file mode 100644
index 000000000..9a0fea7c7
--- /dev/null
+++ b/src/core/ozone/gl_ozone_glx_qt.cpp
@@ -0,0 +1,143 @@
+/****************************************************************************
+**
+** Copyright (C) 2018 The Qt Company Ltd.
+** Contact: https://www.qt.io/licensing/
+**
+** This file is part of the QtWebEngine module of the Qt Toolkit.
+**
+** $QT_BEGIN_LICENSE:LGPL$
+** Commercial License Usage
+** Licensees holding valid commercial Qt licenses may use this file in
+** accordance with the commercial license agreement provided with the
+** Software or, alternatively, in accordance with the terms contained in
+** a written agreement between you and The Qt Company. For licensing terms
+** and conditions see https://www.qt.io/terms-conditions. For further
+** information use the contact form at https://www.qt.io/contact-us.
+**
+** GNU Lesser General Public License Usage
+** Alternatively, this file may be used under the terms of the GNU Lesser
+** General Public License version 3 as published by the Free Software
+** Foundation and appearing in the file LICENSE.LGPL3 included in the
+** packaging of this file. Please review the following information to
+** ensure the GNU Lesser General Public License version 3 requirements
+** will be met: https://www.gnu.org/licenses/lgpl-3.0.html.
+**
+** GNU General Public License Usage
+** Alternatively, this file may be used under the terms of the GNU
+** General Public License version 2.0 or (at your option) the GNU General
+** Public license version 3 or any later version approved by the KDE Free
+** Qt Foundation. The licenses are as published by the Free Software
+** Foundation and appearing in the file LICENSE.GPL2 and LICENSE.GPL3
+** included in the packaging of this file. Please review the following
+** information to ensure the GNU General Public License requirements will
+** be met: https://www.gnu.org/licenses/gpl-2.0.html and
+** https://www.gnu.org/licenses/gpl-3.0.html.
+**
+** $QT_END_LICENSE$
+**
+****************************************************************************/
+
+// Copyright 2016 The Chromium Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+
+#include "gl_ozone_glx_qt.h"
+#include "gl_surface_glx_qt.h"
+#include "ui/gl/gl_context_glx.h"
+#include "ui/gl/gl_gl_api_implementation.h"
+#include "ui/gl/gl_glx_api_implementation.h"
+#include <dlfcn.h>
+
+namespace ui {
+
+bool GLOzoneGLXQt::InitializeGLOneOffPlatform() {
+    if (!gl::GLSurfaceGLXQt::InitializeOneOff()) {
+        LOG(ERROR) << "GLSurfaceGLXQt::InitializeOneOff failed.";
+        return false;
+    }
+    return true;
+}
+
+bool GLOzoneGLXQt::InitializeStaticGLBindings(
+        gl::GLImplementation implementation) {
+
+    base::NativeLibrary library = dlopen(NULL, RTLD_LAZY);
+    if (!library) {
+        LOG(ERROR) << "Failed to open GL context " << dlerror();
+        return false;
+    }
+
+    gl::GLGetProcAddressProc get_proc_address =
+            reinterpret_cast<gl::GLGetProcAddressProc>(
+                base::GetFunctionPointerFromNativeLibrary(library,
+                                                          "glXGetProcAddress"));
+    if (!get_proc_address) {
+        LOG(ERROR) << "glxGetProcAddress not found.";
+        base::UnloadNativeLibrary(library);
+        return false;
+    }
+
+    gl::SetGLGetProcAddressProc(get_proc_address);
+    gl::AddGLNativeLibrary(library);
+    gl::SetGLImplementation(gl::kGLImplementationDesktopGL);
+
+    gl::InitializeStaticGLBindingsGL();
+    gl::InitializeStaticGLBindingsGLX();
+
+    return true;
+}
+
+void GLOzoneGLXQt::InitializeDebugGLBindings() {
+    gl::InitializeDebugGLBindingsGL();
+    gl::InitializeDebugGLBindingsGLX();
+}
+
+void GLOzoneGLXQt::SetDisabledExtensionsPlatform(
+        const std::string& disabled_extensions) {
+    gl::SetDisabledExtensionsGLX(disabled_extensions);
+}
+
+void GLOzoneGLXQt::ShutdownGL() {
+    gl::ClearBindingsGL();
+    gl::ClearBindingsGLX();
+}
+
+bool GLOzoneGLXQt::GetGLWindowSystemBindingInfo(
+        gl::GLWindowSystemBindingInfo* info) {
+    return gl::GetGLWindowSystemBindingInfoGLX(info);
+}
+
+scoped_refptr<gl::GLContext> GLOzoneGLXQt::CreateGLContext(
+        gl::GLShareGroup* share_group,
+        gl::GLSurface* compatible_surface,
+        const gl::GLContextAttribs& attribs) {
+    return gl::InitializeGLContext(new gl::GLContextGLX(share_group),
+                                   compatible_surface, attribs);
+}
+
+scoped_refptr<gl::GLSurface> GLOzoneGLXQt::CreateViewGLSurface(
+        gfx::AcceleratedWidget window) {
+    return nullptr;
+}
+
+scoped_refptr<gl::GLSurface> GLOzoneGLXQt::CreateSurfacelessViewGLSurface(
+        gfx::AcceleratedWidget window) {
+    return nullptr;
+}
+
+scoped_refptr<gl::GLSurface> GLOzoneGLXQt::CreateOffscreenGLSurface(
+        const gfx::Size& size) {
+    scoped_refptr<gl::GLSurface> surface = new gl::GLSurfaceGLXQt(size);
+    if (surface->Initialize(gl::GLSurfaceFormat()))
+        return surface;
+    LOG(WARNING) << "Failed to create offscreen GL surface";
+    return nullptr;
+}
+
+bool GLOzoneGLXQt::InitializeExtensionSettingsOneOffPlatform()
+{
+    return gl::GLSurfaceGLXQt::InitializeExtensionSettingsOneOff();
+}
+
+}  // namespace ui
diff --git a/src/core/ozone/gl_ozone_glx_qt.h b/src/core/ozone/gl_ozone_glx_qt.h
new file mode 100644
index 000000000..ffbd60454
--- /dev/null
+++ b/src/core/ozone/gl_ozone_glx_qt.h
@@ -0,0 +1,85 @@
+/****************************************************************************
+**
+** Copyright (C) 2018 The Qt Company Ltd.
+** Contact: https://www.qt.io/licensing/
+**
+** This file is part of the QtWebEngine module of the Qt Toolkit.
+**
+** $QT_BEGIN_LICENSE:LGPL$
+** Commercial License Usage
+** Licensees holding valid commercial Qt licenses may use this file in
+** accordance with the commercial license agreement provided with the
+** Software or, alternatively, in accordance with the terms contained in
+** a written agreement between you and The Qt Company. For licensing terms
+** and conditions see https://www.qt.io/terms-conditions. For further
+** information use the contact form at https://www.qt.io/contact-us.
+**
+** GNU Lesser General Public License Usage
+** Alternatively, this file may be used under the terms of the GNU Lesser
+** General Public License version 3 as published by the Free Software
+** Foundation and appearing in the file LICENSE.LGPL3 included in the
+** packaging of this file. Please review the following information to
+** ensure the GNU Lesser General Public License version 3 requirements
+** will be met: https://www.gnu.org/licenses/lgpl-3.0.html.
+**
+** GNU General Public License Usage
+** Alternatively, this file may be used under the terms of the GNU
+** General Public License version 2.0 or (at your option) the GNU General
+** Public license version 3 or any later version approved by the KDE Free
+** Qt Foundation. The licenses are as published by the Free Software
+** Foundation and appearing in the file LICENSE.GPL2 and LICENSE.GPL3
+** included in the packaging of this file. Please review the following
+** information to ensure the GNU General Public License requirements will
+** be met: https://www.gnu.org/licenses/gpl-2.0.html and
+** https://www.gnu.org/licenses/gpl-3.0.html.
+**
+** $QT_END_LICENSE$
+**
+****************************************************************************/
+
+#ifndef UI_OZONE_GLX_QT_H_
+#define UI_OZONE_GLX_QT_H
+
+#include "base/macros.h"
+#include "ui/gl/gl_implementation.h"
+#include "ui/ozone/public/gl_ozone.h"
+
+namespace ui {
+
+class GLOzoneGLXQt : public GLOzone {
+
+public:
+    GLOzoneGLXQt() {}
+    ~GLOzoneGLXQt() override {}
+
+    bool InitializeGLOneOffPlatform() override;
+    bool InitializeStaticGLBindings(gl::GLImplementation implementation) override;
+    void InitializeDebugGLBindings() override;
+    bool InitializeExtensionSettingsOneOffPlatform() override;
+    void ShutdownGL() override;
+    void SetDisabledExtensionsPlatform(
+        const std::string& disabled_extensions) override;
+    bool GetGLWindowSystemBindingInfo(
+            gl::GLWindowSystemBindingInfo* info) override;
+
+    scoped_refptr<gl::GLContext> CreateGLContext(
+            gl::GLShareGroup* share_group,
+            gl::GLSurface* compatible_surface,
+            const gl::GLContextAttribs& attribs) override;
+
+    scoped_refptr<gl::GLSurface> CreateViewGLSurface(
+            gfx::AcceleratedWidget window) override;
+
+    scoped_refptr<gl::GLSurface> CreateSurfacelessViewGLSurface(
+            gfx::AcceleratedWidget window) override;
+
+    scoped_refptr<gl::GLSurface> CreateOffscreenGLSurface(
+            const gfx::Size& size) override;
+
+private:
+    DISALLOW_COPY_AND_ASSIGN(GLOzoneGLXQt);
+};
+
+}  // namespace ui
+
+#endif  // UI_OZONE_GLX_QT_H
diff --git a/src/core/ozone/gl_surface_glx_qt.cpp b/src/core/ozone/gl_surface_glx_qt.cpp
index 51b0f58b0..32b85ff77 100644
--- a/src/core/ozone/gl_surface_glx_qt.cpp
+++ b/src/core/ozone/gl_surface_glx_qt.cpp
@@ -41,8 +41,6 @@
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
-#if defined(USE_X11)
-
 #include "gl_context_qt.h"
 #include "ozone/gl_surface_glx_qt.h"
 #include "ui/gl/gl_bindings.h"
@@ -156,7 +154,7 @@ bool GLSurfaceGLXQt::InitializeExtensionSettingsOneOff()
 
     Display* display = static_cast<Display*>(g_display);
     GLSurfaceQt::g_extensions = glXQueryExtensionsString(display, 0);
-    g_driver_glx.InitializeExtensionBindings();
+    g_driver_glx.InitializeExtensionBindings(g_extensions);
     return true;
 }
 
@@ -210,4 +208,3 @@ void* GLSurfaceGLXQt::GetHandle()
 
 } //namespace gl
 
-#endif // defined(USE_X11)
diff --git a/src/core/ozone/ozone_platform_qt.cpp b/src/core/ozone/ozone_platform_qt.cpp
index 8bb5007ef..a13f33301 100644
--- a/src/core/ozone/ozone_platform_qt.cpp
+++ b/src/core/ozone/ozone_platform_qt.cpp
@@ -145,7 +145,6 @@ void OzonePlatformQt::InitializeGPU(const ui::OzonePlatform::InitParams &)
 
 } // namespace
 
-
 OzonePlatform* CreateOzonePlatformQt() { return new OzonePlatformQt; }
 
 gfx::ClientNativePixmapFactory* CreateClientNativePixmapFactoryQt()
diff --git a/src/core/ozone/surface_factory_qt.cpp b/src/core/ozone/surface_factory_qt.cpp
index f21e14c30..d2b2aab8a 100644
--- a/src/core/ozone/surface_factory_qt.cpp
+++ b/src/core/ozone/surface_factory_qt.cpp
@@ -37,6 +37,17 @@
 **
 ****************************************************************************/
 
+#include "surface_factory_qt.h"
+#include "qtwebenginecoreglobal_p.h"
+#include "gl_ozone_egl_qt.h"
+
+#if QT_CONFIG(webengine_system_x11)
+#include "gl_ozone_glx_qt.h"
+#endif
+
+#include "ui/gl/gl_surface.h"
+#include <QGuiApplication>
+
 #if defined(USE_OZONE)
 
 #include "ozone/gl_ozone_egl_qt.h"
@@ -44,16 +55,34 @@
 #include "ui/gl/gl_surface.h"
 namespace QtWebEngineCore {
 
+SurfaceFactoryQt::SurfaceFactoryQt()
+{
+    // Fixme: make better platform switch handling
+    QString platform = qApp->platformName();
+    if (platform == QLatin1String("xcb")) {
+        m_impls.push_back(gl::kGLImplementationDesktopGL);
+    } else {
+        m_impls.push_back(gl::kGLImplementationEGLGLES2);
+    }
+}
+
 std::vector<gl::GLImplementation> SurfaceFactoryQt::GetAllowedGLImplementations()
 {
-    std::vector<gl::GLImplementation> impls;
-    impls.push_back(gl::kGLImplementationEGLGLES2);
-    return impls;
+    return m_impls;
 }
 
 ui::GLOzone* SurfaceFactoryQt::GetGLOzone(gl::GLImplementation implementation)
 {
-    return new GLOzoneEGLQt();
+
+    QString platform = qApp->platformName();
+    if (platform == QLatin1String("xcb")) {
+#if QT_CONFIG(webengine_system_x11)
+        return new ui::GLOzoneGLXQt();
+#endif
+        return nullptr;
+    } else {
+        return new ui::GLOzoneEGLQt();
+    }
 }
 
 } // namespace QtWebEngineCore
diff --git a/src/core/ozone/surface_factory_qt.h b/src/core/ozone/surface_factory_qt.h
index b7991829c..0ac2eca68 100644
--- a/src/core/ozone/surface_factory_qt.h
+++ b/src/core/ozone/surface_factory_qt.h
@@ -48,8 +48,12 @@ namespace QtWebEngineCore {
 
 class SurfaceFactoryQt : public ui::SurfaceFactoryOzone
 {
+public:
+    SurfaceFactoryQt();
     std::vector<gl::GLImplementation> GetAllowedGLImplementations() override;
     ui::GLOzone* GetGLOzone(gl::GLImplementation implementation) override;
+private:
+    std::vector<gl::GLImplementation> m_impls;
 };
 
 } // namespace QtWebEngineCore
diff --git a/src/core/render_widget_host_view_qt.cpp b/src/core/render_widget_host_view_qt.cpp
index b1f7a41dc..3e5d9bc4b 100644
--- a/src/core/render_widget_host_view_qt.cpp
+++ b/src/core/render_widget_host_view_qt.cpp
@@ -887,13 +887,13 @@ void RenderWidgetHostViewQt::OnTextSelectionChanged(content::TextInputManager *t
     if (!selection)
         return;
 
-#if defined(USE_X11)
+#if defined(USE_OZONE)
     if (!selection->selected_text().empty() && selection->user_initiated()) {
         // Set the CLIPBOARD_TYPE_SELECTION to the ui::Clipboard.
         ui::ScopedClipboardWriter clipboard_writer(ui::CLIPBOARD_TYPE_SELECTION);
         clipboard_writer.WriteText(selection->selected_text());
     }
-#endif // defined(USE_X11)
+#endif // defined(USE_OZONE)
 
     m_imState |= ImStateFlags::TextSelectionUpdated;
     if (m_imState == ImStateFlags::AllFlags
diff --git a/src/core/web_engine_context.cpp b/src/core/web_engine_context.cpp
index 4eb689d93..33a5a5e0d 100644
--- a/src/core/web_engine_context.cpp
+++ b/src/core/web_engine_context.cpp
@@ -316,14 +316,6 @@ WebEngineContext::WebEngineContext()
     , m_browserRunner(content::BrowserMainRunner::Create())
     , m_globalQObject(new QObject())
 {
-#if defined(USE_X11)
-    QString platform = qApp->platformName();
-    if (platform != QLatin1String("xcb")) {
-         qWarning("WebEngine compiled with X11 support, however qpa backend is not xcb. "
-                  "This may fail.");
-    }
-#endif
-
 #ifdef Q_OS_LINUX
     // Call qputenv before BrowserMainRunnerImpl::Initialize is called.
     // http://crbug.com/245466
@@ -453,9 +445,6 @@ WebEngineContext::WebEngineContext()
             // If the native handle is QEGLNativeContext try to use GL ES/2, if there is no native handle
             // assume we are using wayland and try GL ES/2, and finally Ozone demands GL ES/2 too.
             if (qt_gl_global_share_context()->nativeHandle().isNull()
-#ifdef USE_OZONE
-                || true
-#endif
                 || !strcmp(qt_gl_global_share_context()->nativeHandle().typeName(), "QEGLNativeContext"))
             {
                 if (qt_gl_global_share_context()->isOpenGLES()) {