Migrate render_view_observer_qt to mojo

Since mojo interface no longer works on render view, but
on render frame rename the class to be WebEnginePageHost
and WebEnginePageRenderFrame

Keep SetBackgroundColor render message, since it is required
to things work.

Change-Id: I4d6b70dd448926f8ac2d75d2b87f3d490a4cfefb
Reviewed-by: Allan Sandfeld Jensen <allan.jensen@qt.io>

11 files changed, 152 insertions, 130 deletions

diff --git a/src/core/common/qt_messages.h b/src/core/common/qt_messages.h
index 211c3c3de..7713b6286 100644
--- a/src/core/common/qt_messages.h
+++ b/src/core/common/qt_messages.h
@@ -12,37 +12,15 @@
 
 #define IPC_MESSAGE_START QtMsgStart
 
-//-----------------------------------------------------------------------------
-// RenderView messages
-// These are messages sent from the browser to the renderer process.
-
-IPC_MESSAGE_ROUTED1(RenderViewObserverQt_FetchDocumentMarkup,
-                    uint64_t /* requestId */)
-
-IPC_MESSAGE_ROUTED1(RenderViewObserverQt_FetchDocumentInnerText,
-                    uint64_t /* requestId */)
-
-IPC_MESSAGE_ROUTED1(RenderViewObserverQt_SetBackgroundColor,
-                    uint32_t /* color */)
-
 // Tells the renderer whether or not a file system access has been allowed.
 IPC_MESSAGE_ROUTED2(QtWebEngineMsg_RequestFileSystemAccessAsyncResponse,
                     int  /* request_id */,
                     bool /* allowed */)
 
-
 //-----------------------------------------------------------------------------
 // WebContents messages
 // These are messages sent from the renderer back to the browser process.
 
-IPC_MESSAGE_ROUTED2(RenderViewObserverHostQt_DidFetchDocumentMarkup,
-                    uint64_t /* requestId */,
-                    base::string16 /* markup */)
-
-IPC_MESSAGE_ROUTED2(RenderViewObserverHostQt_DidFetchDocumentInnerText,
-                    uint64_t /* requestId */,
-                    base::string16 /* innerText */)
-
 IPC_MESSAGE_ROUTED0(RenderViewObserverHostQt_DidFirstVisuallyNonEmptyLayout)
 
 //-----------------------------------------------------------------------------
diff --git a/src/core/core_chromium.pri b/src/core/core_chromium.pri
index 8cc9c8ef8..248b245b4 100644
--- a/src/core/core_chromium.pri
+++ b/src/core/core_chromium.pri
@@ -110,11 +110,11 @@ SOURCES = \
         renderer/content_renderer_client_qt.cpp \
         renderer/content_settings_observer_qt.cpp \
         renderer/render_frame_observer_qt.cpp \
-        renderer/render_view_observer_qt.cpp \
+        renderer/web_engine_page_render_frame.cpp \
         renderer/render_configuration.cpp \
         renderer/user_resource_controller.cpp \
         renderer/plugins/plugin_placeholder_qt.cpp \
-        renderer_host/render_view_observer_host_qt.cpp \
+        renderer_host/web_engine_page_host.cpp \
         renderer_host/user_resource_controller_host.cpp \
         resource_bundle_qt.cpp \
         resource_context_qt.cpp \
@@ -215,11 +215,11 @@ HEADERS = \
         renderer/content_renderer_client_qt.h \
         renderer/content_settings_observer_qt.h \
         renderer/render_frame_observer_qt.h \
-        renderer/render_view_observer_qt.h \
+        renderer/web_engine_page_render_frame.h \
         renderer/render_configuration.h \
         renderer/user_resource_controller.h \
         renderer/plugins/plugin_placeholder_qt.h \
-        renderer_host/render_view_observer_host_qt.h \
+        renderer_host/web_engine_page_host.h \
         renderer_host/user_resource_controller_host.h \
         request_controller.h \
         resource_context_qt.h \
diff --git a/src/core/render_widget_host_view_qt.cpp b/src/core/render_widget_host_view_qt.cpp
index 36ffbea57..0f53228c7 100644
--- a/src/core/render_widget_host_view_qt.cpp
+++ b/src/core/render_widget_host_view_qt.cpp
@@ -527,8 +527,6 @@ void RenderWidgetHostViewQt::UpdateBackgroundColor()
     content::RenderViewHost *rvh = content::RenderViewHost::From(host());
     if (color == SK_ColorTRANSPARENT)
         host()->owner_delegate()->SetBackgroundOpaque(false);
-    else
-        host()->Send(new RenderViewObserverQt_SetBackgroundColor(rvh->GetRoutingID(), color));
 }
 
 // Return value indicates whether the mouse is locked successfully or not.
diff --git a/src/core/renderer/content_renderer_client_qt.cpp b/src/core/renderer/content_renderer_client_qt.cpp
index 62c837cf0..103c73ed0 100644
--- a/src/core/renderer/content_renderer_client_qt.cpp
+++ b/src/core/renderer/content_renderer_client_qt.cpp
@@ -83,7 +83,7 @@
 
 #include "common/qt_messages.h"
 #include "renderer/render_frame_observer_qt.h"
-#include "renderer/render_view_observer_qt.h"
+#include "renderer/web_engine_page_render_frame.h"
 #include "renderer/render_configuration.h"
 #include "renderer/user_resource_controller.h"
 #if QT_CONFIG(webengine_webchannel)
@@ -188,20 +188,16 @@ void ContentRendererClientQt::ExposeInterfacesToBrowser(mojo::BinderMap* binders
 #endif
 }
 
-void ContentRendererClientQt::RenderViewCreated(content::RenderView *render_view)
-{
-    // RenderViewObservers destroy themselves with their RenderView.
-    new RenderViewObserverQt(render_view);
-}
-
 void ContentRendererClientQt::RenderFrameCreated(content::RenderFrame *render_frame)
 {
     QtWebEngineCore::RenderFrameObserverQt *render_frame_observer =
             new QtWebEngineCore::RenderFrameObserverQt(render_frame, m_webCacheImpl.data());
+    if (render_frame->IsMainFrame()) {
 #if QT_CONFIG(webengine_webchannel)
-    if (render_frame->IsMainFrame())
         new WebChannelIPCTransport(render_frame);
 #endif
+        new WebEnginePageRenderFrame(render_frame);
+    }
 
     m_userResourceController->renderFrameCreated(render_frame);
 
diff --git a/src/core/renderer/content_renderer_client_qt.h b/src/core/renderer/content_renderer_client_qt.h
index 3ac04fa34..91bce972f 100644
--- a/src/core/renderer/content_renderer_client_qt.h
+++ b/src/core/renderer/content_renderer_client_qt.h
@@ -88,7 +88,6 @@ public:
     // content::ContentRendererClient:
     void RenderThreadStarted() override;
     void ExposeInterfacesToBrowser(mojo::BinderMap* binders) override;
-    void RenderViewCreated(content::RenderView *render_view) override;
     void RenderFrameCreated(content::RenderFrame *render_frame) override;
     bool ShouldSuppressErrorPage(content::RenderFrame *, const GURL &) override;
     bool HasErrorPage(int http_status_code) override;
diff --git a/src/core/renderer/render_view_observer_qt.cpp b/src/core/renderer/web_engine_page_render_frame.cpp
index 5b0b9a77d..add1788d6 100644
--- a/src/core/renderer/render_view_observer_qt.cpp
+++ b/src/core/renderer/web_engine_page_render_frame.cpp
@@ -37,11 +37,11 @@
 **
 ****************************************************************************/
 
-#include "renderer/render_view_observer_qt.h"
+#include "renderer/web_engine_page_render_frame.h"
+#include "content/public/renderer/render_frame.h"
+#include "third_party/blink/public/common/associated_interfaces/associated_interface_provider.h"
+#include "third_party/blink/public/common/associated_interfaces/associated_interface_registry.h"
 
-#include "common/qt_messages.h"
-
-#include "content/public/renderer/render_view.h"
 #include "third_party/blink/public/web/web_document.h"
 #include "third_party/blink/public/web/web_element.h"
 #include "third_party/blink/public/web/web_frame.h"
@@ -50,45 +50,45 @@
 #include "third_party/blink/public/web/web_local_frame.h"
 #include "third_party/blink/public/web/web_view.h"
 
-RenderViewObserverQt::RenderViewObserverQt(content::RenderView *render_view) : content::RenderViewObserver(render_view)
-{}
+namespace QtWebEngineCore {
 
-void RenderViewObserverQt::onFetchDocumentMarkup(quint64 requestId)
+WebEnginePageRenderFrame::WebEnginePageRenderFrame(content::RenderFrame *render_frame)
+    : content::RenderFrameObserver(render_frame), m_binding(this)
 {
-    blink::WebString markup;
-    if (render_view()->GetWebView()->MainFrame()->IsWebLocalFrame())
-        markup = blink::WebFrameContentDumper::DumpAsMarkup(
-                static_cast<blink::WebLocalFrame *>(render_view()->GetWebView()->MainFrame()));
-    Send(new RenderViewObserverHostQt_DidFetchDocumentMarkup(routing_id(), requestId, markup.Utf16()));
+    render_frame->GetAssociatedInterfaceRegistry()->AddInterface(
+            base::BindRepeating(&WebEnginePageRenderFrame::BindReceiver, base::Unretained(this)));
 }
 
-void RenderViewObserverQt::onFetchDocumentInnerText(quint64 requestId)
+void WebEnginePageRenderFrame::BindReceiver(
+        mojo::PendingAssociatedReceiver<qtwebenginepage::mojom::WebEnginePageRenderFrame> receiver)
 {
-    blink::WebString text;
-    if (render_view()->GetWebView()->MainFrame()->IsWebLocalFrame())
-        text = blink::WebFrameContentDumper::DumpWebViewAsText(render_view()->GetWebView(),
-                                                               std::numeric_limits<std::size_t>::max());
-    Send(new RenderViewObserverHostQt_DidFetchDocumentInnerText(routing_id(), requestId, text.Utf16()));
+    m_binding.Bind(std::move(receiver));
 }
 
-void RenderViewObserverQt::onSetBackgroundColor(quint32 color)
+void WebEnginePageRenderFrame::FetchDocumentMarkup(uint64_t requestId,
+                                                   FetchDocumentMarkupCallback callback)
 {
-    render_view()->GetWebView()->SetBaseBackgroundColorOverride(color);
+    blink::WebString markup =
+            blink::WebFrameContentDumper::DumpAsMarkup(render_frame()->GetWebFrame());
+    std::move(callback).Run(requestId, markup.Utf8());
 }
 
-void RenderViewObserverQt::OnDestruct()
+void WebEnginePageRenderFrame::FetchDocumentInnerText(uint64_t requestId,
+                                                      FetchDocumentInnerTextCallback callback)
 {
-    delete this;
+    blink::WebString text = blink::WebFrameContentDumper::DumpWebViewAsText(
+            render_frame()->GetWebFrame()->View(), std::numeric_limits<std::size_t>::max());
+    std::move(callback).Run(requestId, text.Utf8());
+}
+
+void WebEnginePageRenderFrame::SetBackgroundColor(uint32_t color)
+{
+    render_frame()->GetWebFrame()->View()->SetBaseBackgroundColorOverride(color);
 }
 
-bool RenderViewObserverQt::OnMessageReceived(const IPC::Message &message)
+void WebEnginePageRenderFrame::OnDestruct()
 {
-    bool handled = true;
-    IPC_BEGIN_MESSAGE_MAP(RenderViewObserverQt, message)
-        IPC_MESSAGE_HANDLER(RenderViewObserverQt_FetchDocumentMarkup, onFetchDocumentMarkup)
-        IPC_MESSAGE_HANDLER(RenderViewObserverQt_FetchDocumentInnerText, onFetchDocumentInnerText)
-        IPC_MESSAGE_HANDLER(RenderViewObserverQt_SetBackgroundColor, onSetBackgroundColor)
-        IPC_MESSAGE_UNHANDLED(handled = false)
-    IPC_END_MESSAGE_MAP()
-    return handled;
+    delete this;
+}
+
 }
diff --git a/src/core/renderer/render_view_observer_qt.h b/src/core/renderer/web_engine_page_render_frame.h
index 5c555b222..3fb4657c5 100644
--- a/src/core/renderer/render_view_observer_qt.h
+++ b/src/core/renderer/web_engine_page_render_frame.h
@@ -1,6 +1,6 @@
 /****************************************************************************
 **
-** Copyright (C) 2016 The Qt Company Ltd.
+** Copyright (C) 2020 The Qt Company Ltd.
 ** Contact: https://www.qt.io/licensing/
 **
 ** This file is part of the QtWebEngine module of the Qt Toolkit.
@@ -36,28 +36,40 @@
 ** $QT_END_LICENSE$
 **
 ****************************************************************************/
-#ifndef RENDER_VIEW_OBSERVER_QT_H
-#define RENDER_VIEW_OBSERVER_QT_H
+#ifndef WEB_ENGINE_PAGE_RENDER_FRAME_H
+#define WEB_ENGINE_PAGE_RENDER_FRAME_H
 
-#include "content/public/renderer/render_view_observer.h"
+#include "content/public/renderer/render_frame_observer.h"
+#include "mojo/public/cpp/bindings/associated_receiver.h"
+#include "qtwebengine/browser/qtwebenginepage.mojom.h"
 
-#include <QtGlobal>
+namespace content {
+class RenderFrame;
+}
 
-class RenderViewObserverQt : public content::RenderViewObserver
+namespace QtWebEngineCore {
+
+class WebEnginePageRenderFrame : private content::RenderFrameObserver,
+                                 public qtwebenginepage::mojom::WebEnginePageRenderFrame
 {
 public:
-    RenderViewObserverQt(content::RenderView *render_view);
+    WebEnginePageRenderFrame(content::RenderFrame *render_frame);
+    WebEnginePageRenderFrame(const WebEnginePageRenderFrame &) = delete;
+    WebEnginePageRenderFrame &operator=(const WebEnginePageRenderFrame &) = delete;
 
 private:
-    void onFetchDocumentMarkup(quint64 requestId);
-    void onFetchDocumentInnerText(quint64 requestId);
-    void onSetBackgroundColor(quint32 color);
-
+    void FetchDocumentMarkup(uint64_t requestId, FetchDocumentMarkupCallback callback) override;
+    void FetchDocumentInnerText(uint64_t requestId,
+                                FetchDocumentInnerTextCallback callback) override;
+    void SetBackgroundColor(uint32_t color) override;
     void OnDestruct() override;
+    void
+    BindReceiver(mojo::PendingAssociatedReceiver<qtwebenginepage::mojom::WebEnginePageRenderFrame>
+                         receiver);
 
-    bool OnMessageReceived(const IPC::Message &message) override;
-
-    DISALLOW_COPY_AND_ASSIGN(RenderViewObserverQt);
+private:
+    mojo::AssociatedReceiver<qtwebenginepage::mojom::WebEnginePageRenderFrame> m_binding;
 };
+} // namespace
 
-#endif // RENDER_VIEW_OBSERVER_QT_H
+#endif // WEB_ENGINE_PAGE_RENDER_FRAME_H
diff --git a/src/core/renderer_host/render_view_observer_host_qt.cpp b/src/core/renderer_host/web_engine_page_host.cpp
index 165a9d86a..36907ef5a 100644
--- a/src/core/renderer_host/render_view_observer_host_qt.cpp
+++ b/src/core/renderer_host/web_engine_page_host.cpp
@@ -37,59 +37,76 @@
 **
 ****************************************************************************/
 
-#include "render_view_observer_host_qt.h"
+#include "web_engine_page_host.h"
 
-#include "common/qt_messages.h"
-#include "content/public/browser/render_view_host.h"
+#include "qtwebengine/browser/qtwebenginepage.mojom.h"
 #include "content/public/browser/web_contents.h"
 
 #include "render_widget_host_view_qt.h"
 #include "type_conversion.h"
 #include "web_contents_adapter_client.h"
+#include "third_party/blink/public/common/associated_interfaces/associated_interface_provider.h"
 
 namespace QtWebEngineCore {
 
-RenderViewObserverHostQt::RenderViewObserverHostQt(content::WebContents *webContents, WebContentsAdapterClient *adapterClient)
-    : content::WebContentsObserver(webContents)
-    , m_adapterClient(adapterClient)
+WebEnginePageHost::WebEnginePageHost(content::WebContents *webContents,
+                                     WebContentsAdapterClient *adapterClient)
+    : content::WebContentsObserver(webContents), m_adapterClient(adapterClient)
 {
 }
 
-void RenderViewObserverHostQt::fetchDocumentMarkup(quint64 requestId)
+void WebEnginePageHost::FetchDocumentMarkup(uint64_t requestId)
 {
-    web_contents()->GetRenderViewHost()->Send(
-                new RenderViewObserverQt_FetchDocumentMarkup(
-                        web_contents()->GetRenderViewHost()->GetRoutingID(), requestId));
+    auto &remote = GetWebEnginePageRenderFrame(web_contents()->GetMainFrame());
+    remote->FetchDocumentMarkup(
+            requestId,
+            base::BindOnce(&WebEnginePageHost::OnDidFetchDocumentMarkup, base::Unretained(this)));
 }
 
-void RenderViewObserverHostQt::fetchDocumentInnerText(quint64 requestId)
+void WebEnginePageHost::FetchDocumentInnerText(uint64_t requestId)
 {
-    web_contents()->GetRenderViewHost()->Send(
-                new RenderViewObserverQt_FetchDocumentInnerText(
-                        web_contents()->GetRenderViewHost()->GetRoutingID(), requestId));
+    auto &remote = GetWebEnginePageRenderFrame(web_contents()->GetMainFrame());
+    remote->FetchDocumentInnerText(requestId,
+                                   base::BindOnce(&WebEnginePageHost::OnDidFetchDocumentInnerText,
+                                                  base::Unretained(this)));
 }
 
-bool RenderViewObserverHostQt::OnMessageReceived(const IPC::Message &message)
+void WebEnginePageHost::OnDidFetchDocumentMarkup(uint64_t requestId, const std::string &markup)
 {
-    bool handled = true;
-    IPC_BEGIN_MESSAGE_MAP(RenderViewObserverHostQt, message)
-        IPC_MESSAGE_HANDLER(RenderViewObserverHostQt_DidFetchDocumentMarkup,
-                            onDidFetchDocumentMarkup)
-        IPC_MESSAGE_HANDLER(RenderViewObserverHostQt_DidFetchDocumentInnerText,
-                            onDidFetchDocumentInnerText)
-        IPC_MESSAGE_UNHANDLED(handled = false)
-    IPC_END_MESSAGE_MAP()
-    return handled;
+    m_adapterClient->didFetchDocumentMarkup(requestId, toQt(markup));
 }
 
-void RenderViewObserverHostQt::onDidFetchDocumentMarkup(quint64 requestId, const base::string16 &markup)
+void WebEnginePageHost::OnDidFetchDocumentInnerText(uint64_t requestId,
+                                                    const std::string &innerText)
 {
-    m_adapterClient->didFetchDocumentMarkup(requestId, toQt(markup));
+    m_adapterClient->didFetchDocumentInnerText(requestId, toQt(innerText));
 }
 
-void RenderViewObserverHostQt::onDidFetchDocumentInnerText(quint64 requestId, const base::string16 &innerText)
+void WebEnginePageHost::RenderFrameDeleted(content::RenderFrameHost *render_frame)
 {
-    m_adapterClient->didFetchDocumentInnerText(requestId, toQt(innerText));
+    m_renderFrames.erase(render_frame);
+}
+
+void WebEnginePageHost::SetBackgroundColor(uint32_t color)
+{
+    auto &remote = GetWebEnginePageRenderFrame(web_contents()->GetMainFrame());
+    remote->SetBackgroundColor(color);
+}
+
+const WebEnginePageRenderFrameRemote &
+WebEnginePageHost::GetWebEnginePageRenderFrame(content::RenderFrameHost *rfh)
+{
+    auto it = m_renderFrames.find(rfh);
+    if (it == m_renderFrames.end()) {
+        WebEnginePageRenderFrameRemote remote;
+        rfh->GetRemoteAssociatedInterfaces()->GetInterface(remote.BindNewEndpointAndPassReceiver());
+        it = m_renderFrames.insert(std::make_pair(rfh, std::move(remote))).first;
+    } else if (it->second.is_bound() && !it->second.is_connected()) {
+        it->second.reset();
+        rfh->GetRemoteAssociatedInterfaces()->GetInterface(&it->second);
+    }
+
+    return it->second;
 }
 
 } // namespace QtWebEngineCore
diff --git a/src/core/renderer_host/render_view_observer_host_qt.h b/src/core/renderer_host/web_engine_page_host.h
index 8590ecbc5..f305d22ea 100644
--- a/src/core/renderer_host/render_view_observer_host_qt.h
+++ b/src/core/renderer_host/web_engine_page_host.h
@@ -37,8 +37,8 @@
 **
 ****************************************************************************/
 
-#ifndef RENDER_VIEW_OBSERVER_HOST_QT_H
-#define RENDER_VIEW_OBSERVER_HOST_QT_H
+#ifndef WEB_ENGINE_PAGE_HOST_H
+#define WEB_ENGINE_PAGE_HOST_H
 
 #include "content/public/browser/web_contents_observer.h"
 
@@ -48,25 +48,43 @@ namespace content {
 class WebContents;
 }
 
+namespace mojo {
+template<typename Type>
+class AssociatedRemote;
+}
+
+namespace qtwebenginepage {
+namespace mojom {
+class WebEnginePageRenderFrame;
+}
+}
+
 namespace QtWebEngineCore {
 
+using WebEnginePageRenderFrameRemote = mojo::AssociatedRemote<qtwebenginepage::mojom::WebEnginePageRenderFrame>;
+
 class WebContentsAdapterClient;
 
-class RenderViewObserverHostQt : public content::WebContentsObserver
+class WebEnginePageHost : public content::WebContentsObserver
 {
 public:
-    RenderViewObserverHostQt(content::WebContents *, WebContentsAdapterClient *adapterClient);
-    void fetchDocumentMarkup(quint64 requestId);
-    void fetchDocumentInnerText(quint64 requestId);
+    WebEnginePageHost(content::WebContents *, WebContentsAdapterClient *adapterClient);
+    void FetchDocumentMarkup(uint64_t requestId);
+    void FetchDocumentInnerText(uint64_t requestId);
+    void RenderFrameDeleted(content::RenderFrameHost *render_frame) override;
+    void SetBackgroundColor(uint32_t color);
 
 private:
-    bool OnMessageReceived(const IPC::Message &message) override;
-    void onDidFetchDocumentMarkup(quint64 requestId, const base::string16 &markup);
-    void onDidFetchDocumentInnerText(quint64 requestId, const base::string16 &innerText);
+    void OnDidFetchDocumentMarkup(uint64_t requestId, const std::string &markup);
+    void OnDidFetchDocumentInnerText(uint64_t requestId, const std::string &innerText);
+    const WebEnginePageRenderFrameRemote &
+    GetWebEnginePageRenderFrame(content::RenderFrameHost *rfh);
 
+private:
     WebContentsAdapterClient *m_adapterClient;
+    std::map<content::RenderFrameHost *, WebEnginePageRenderFrameRemote> m_renderFrames;
 };
 
 } // namespace QtWebEngineCore
 
-#endif // RENDER_VIEW_OBSERVER_HOST_QT_H
+#endif // WEB_ENGINE_PAGE_HOST_H
diff --git a/src/core/web_contents_adapter.cpp b/src/core/web_contents_adapter.cpp
index a44b3316e..18fa9d922 100644
--- a/src/core/web_contents_adapter.cpp
+++ b/src/core/web_contents_adapter.cpp
@@ -53,7 +53,7 @@
 #include "profile_adapter.h"
 #include "profile_qt.h"
 #include "qwebenginecallback_p.h"
-#include "renderer_host/render_view_observer_host_qt.h"
+#include "renderer_host/web_engine_page_host.h"
 #include "render_widget_host_view_qt.h"
 #include "type_conversion.h"
 #include "web_contents_view_qt.h"
@@ -96,6 +96,7 @@
 #include "ui/base/clipboard/clipboard_constants.h"
 #include "ui/base/clipboard/custom_data_helper.h"
 #include "ui/gfx/font_render_params.h"
+#include "qtwebengine/browser/qtwebenginepage.mojom.h"
 
 #if QT_CONFIG(webengine_webchannel)
 #include "renderer_host/web_channel_ipc_transport_host.h"
@@ -511,7 +512,7 @@ void WebContentsAdapter::initialize(content::SiteInstance *site)
 
     // Create and attach observers to the WebContents.
     m_webContentsDelegate.reset(new WebContentsDelegateQt(m_webContents.get(), m_adapterClient));
-    m_renderViewObserverHost.reset(new RenderViewObserverHostQt(m_webContents.get(), m_adapterClient));
+    m_pageHost.reset(new WebEnginePageHost(m_webContents.get(), m_adapterClient));
 
     // Let the WebContent's view know about the WebContentsAdapterClient.
     WebContentsViewQt* contentsView = static_cast<WebContentsViewQt*>(static_cast<content::WebContentsImpl*>(m_webContents.get())->GetView());
@@ -1078,14 +1079,14 @@ quint64 WebContentsAdapter::runJavaScriptCallbackResult(const QString &javaScrip
 quint64 WebContentsAdapter::fetchDocumentMarkup()
 {
     CHECK_INITIALIZED(0);
-    m_renderViewObserverHost->fetchDocumentMarkup(m_nextRequestId);
+    m_pageHost->FetchDocumentMarkup(m_nextRequestId);
     return m_nextRequestId++;
 }
 
 quint64 WebContentsAdapter::fetchDocumentInnerText()
 {
     CHECK_INITIALIZED(0);
-    m_renderViewObserverHost->fetchDocumentInnerText(m_nextRequestId);
+    m_pageHost->FetchDocumentInnerText(m_nextRequestId);
     return m_nextRequestId++;
 }
 
@@ -1415,8 +1416,11 @@ void WebContentsAdapter::handlePendingMouseLockPermission()
 void WebContentsAdapter::setBackgroundColor(const QColor &color)
 {
     CHECK_INITIALIZED();
+    SkColor c = toSk(color);
     if (content::RenderWidgetHostView *rwhv = m_webContents->GetRenderWidgetHostView())
-        rwhv->SetBackgroundColor(toSk(color));
+        rwhv->SetBackgroundColor(c);
+    if (color != Qt::transparent)
+        m_pageHost->SetBackgroundColor(c);
 }
 
 content::WebContents *WebContentsAdapter::webContents() const
@@ -1990,14 +1994,14 @@ void WebContentsAdapter::discard()
     m_webChannel = nullptr;
     m_webChannelWorld = 0;
 #endif
-    m_renderViewObserverHost.reset();
+    m_pageHost.reset();
     m_webContentsDelegate.reset();
     m_webContents.reset();
 
     m_webContents = std::move(nullContents);
     initializeRenderPrefs();
     m_webContentsDelegate = std::move(nullDelegate);
-    m_renderViewObserverHost.reset(new RenderViewObserverHostQt(m_webContents.get(), m_adapterClient));
+    m_pageHost.reset(new WebEnginePageHost(m_webContents.get(), m_adapterClient));
     WebContentsViewQt *contentsView =
             static_cast<WebContentsViewQt *>(static_cast<content::WebContentsImpl *>(m_webContents.get())->GetView());
     contentsView->setClient(m_adapterClient);
diff --git a/src/core/web_contents_adapter.h b/src/core/web_contents_adapter.h
index d833314f2..5bc85453c 100644
--- a/src/core/web_contents_adapter.h
+++ b/src/core/web_contents_adapter.h
@@ -90,7 +90,7 @@ class FaviconManager;
 class FindTextHelper;
 class MessagePassingInterface;
 class ProfileQt;
-class RenderViewObserverHostQt;
+class WebEnginePageHost;
 class WebChannelIPCTransportHost;
 class WebEngineContext;
 
@@ -261,7 +261,7 @@ private:
     ProfileAdapter *m_profileAdapter;
     std::unique_ptr<content::WebContents> m_webContents;
     std::unique_ptr<WebContentsDelegateQt> m_webContentsDelegate;
-    std::unique_ptr<RenderViewObserverHostQt> m_renderViewObserverHost;
+    std::unique_ptr<WebEnginePageHost> m_pageHost;
 #if QT_CONFIG(webengine_webchannel)
     std::unique_ptr<WebChannelIPCTransportHost> m_webChannelTransport;
     QWebChannel *m_webChannel;