Add InputEventObserver to child frames

RenderWidgetHostViewChildFrame does not Ack mouse wheel events.
RenderWidgetHostViewQt::handleWheelEvent expects Ack on every event.

Origin-Agent-Cluster is a HTTP response header that instructs
the browser to prevent synchronous scripting between same-site
cross-origin pages. Chromium also uses this header as a hint
that an origin should get its own separate resources, such as a
dedicated process. That's where child frames are created.
This feature is implemented in chromium 88.

Add observer to child frames that responds to wheel events.
Add test for wheel/scroll events on child frames.

Pick-to: 6.5
Fixes: QTBUG-109348
Change-Id: I20439a9068c5c2f8416a350891a6cf8830e1a5d6
Reviewed-by: Allan Sandfeld Jensen <allan.jensen@qt.io>

4 files changed, 46 insertions, 39 deletions

diff --git a/src/core/extensions/extension_web_contents_observer_qt.cpp b/src/core/extensions/extension_web_contents_observer_qt.cpp
index 22092be30..a33954a20 100644
--- a/src/core/extensions/extension_web_contents_observer_qt.cpp
+++ b/src/core/extensions/extension_web_contents_observer_qt.cpp
@@ -41,17 +41,8 @@ void ExtensionWebContentsObserverQt::CreateForWebContents(content::WebContents *
 void ExtensionWebContentsObserverQt::RenderFrameCreated(content::RenderFrameHost *render_frame_host)
 {
     ExtensionWebContentsObserver::RenderFrameCreated(render_frame_host);
-
-    if (web_contents()->IsInnerWebContentsForGuest() && static_cast<content::RenderFrameHostImpl *>(render_frame_host)->is_local_root_subframe()) {
-        content::WebContents *parent = web_contents()->GetOutermostWebContents();
-        QtWebEngineCore::RenderWidgetHostViewQt *main_rwhv = static_cast<QtWebEngineCore::RenderWidgetHostViewQt *>(parent->GetRenderWidgetHostView());
-        // Main frame of guest WebContents
-        content::RenderWidgetHost *guest_render_widget_host = web_contents()->GetRenderViewHost()->GetWidget();
-        main_rwhv->addGuest(guest_render_widget_host);
-        // The frame which holds the actual PDF content inside the guest
-        content::RenderWidgetHost *pdf_render_widget_host = render_frame_host->GetRenderWidgetHost();
-        main_rwhv->addGuest(pdf_render_widget_host);
-    }
+    QtWebEngineCore::RenderWidgetHostViewQt::registerInputEventObserver(web_contents(),
+                                                                        render_frame_host);
 
     const Extension *extension = GetExtensionFromFrame(render_frame_host, false);
     if (!extension)
diff --git a/src/core/render_widget_host_view_qt.cpp b/src/core/render_widget_host_view_qt.cpp
index 19b9f462c..3d4e5bbc2 100644
--- a/src/core/render_widget_host_view_qt.cpp
+++ b/src/core/render_widget_host_view_qt.cpp
@@ -18,6 +18,7 @@
 #include "components/viz/common/surfaces/frame_sink_id_allocator.h"
 #include "components/viz/host/host_frame_sink_manager.h"
 #include "content/browser/compositor/image_transport_factory.h"
+#include "content/browser/renderer_host/render_frame_host_impl.h"
 #include "content/browser/renderer_host/frame_tree.h"
 #include "content/browser/renderer_host/frame_tree_node.h"
 #include "content/browser/renderer_host/cursor_manager.h"
@@ -29,6 +30,7 @@
 #include "content/browser/renderer_host/ui_events_helper.h"
 #include "content/common/content_switches_internal.h"
 #include "content/common/cursors/webcursor.h"
+#include "content/public/browser/web_contents.h"
 #include "third_party/skia/include/core/SkColor.h"
 #include "ui/base/cursor/cursor.h"
 #include "ui/base/resource/resource_bundle.h"
@@ -141,33 +143,10 @@ public:
     }
 };
 
-class GuestInputEventObserverQt : public content::RenderWidgetHost::InputEventObserver
-{
-public:
-    GuestInputEventObserverQt(RenderWidgetHostViewQt *rwhv)
-        : m_rwhv(rwhv)
-    {
-    }
-    ~GuestInputEventObserverQt() {}
-
-    void OnInputEvent(const blink::WebInputEvent&) override {}
-    void OnInputEventAck(blink::mojom::InputEventResultSource,
-                         blink::mojom::InputEventResultState state,
-                         const blink::WebInputEvent &event) override
-    {
-        if (event.GetType() == blink::WebInputEvent::Type::kMouseWheel)
-            m_rwhv->WheelEventAck(static_cast<const blink::WebMouseWheelEvent &>(event), state);
-    }
-
-private:
-    RenderWidgetHostViewQt *m_rwhv;
-};
-
 RenderWidgetHostViewQt::RenderWidgetHostViewQt(content::RenderWidgetHost *widget)
     : content::RenderWidgetHostViewBase::RenderWidgetHostViewBase(widget)
     , m_taskRunner(base::ThreadTaskRunnerHandle::Get())
     , m_gestureProvider(QtGestureProviderConfig(), this)
-    , m_guestInputEventObserver(new GuestInputEventObserverQt(this))
     , m_frameSinkId(host()->GetFrameSinkId())
     , m_delegateClient(new RenderWidgetHostViewQtDelegateClient(this))
 {
@@ -247,9 +226,34 @@ void RenderWidgetHostViewQt::setAdapterClient(WebContentsAdapterClient *adapterC
                                                             m_adapterClient = nullptr; });
 }
 
-void RenderWidgetHostViewQt::addGuest(content::RenderWidgetHost *rwh)
+void RenderWidgetHostViewQt::OnInputEventAck(blink::mojom::InputEventResultSource,
+                                             blink::mojom::InputEventResultState state,
+                                             const blink::WebInputEvent &event)
 {
-    rwh->AddInputEventObserver(m_guestInputEventObserver.get());
+    if (event.GetType() == blink::WebInputEvent::Type::kMouseWheel)
+        WheelEventAck(static_cast<const blink::WebMouseWheelEvent &>(event), state);
+}
+
+// static
+// Called when new child/guest renderframes created.
+void RenderWidgetHostViewQt::registerInputEventObserver(content::WebContents *webContents,
+                                                        content::RenderFrameHost *rfh)
+{
+    if (static_cast<content::RenderFrameHostImpl *>(rfh)->is_local_root_subframe()) {
+        content::WebContents *parent = webContents->GetOutermostWebContents();
+        QtWebEngineCore::RenderWidgetHostViewQt *mainRwhv =
+                static_cast<QtWebEngineCore::RenderWidgetHostViewQt *>(
+                        parent->GetRenderWidgetHostView());
+        // Child (originAgentCluster) or guest (pdf) frame that is embedded into the main frame
+        content::RenderWidgetHost *childFrame = rfh->GetRenderWidgetHost();
+        childFrame->AddInputEventObserver(mainRwhv);
+
+        if (webContents->IsInnerWebContentsForGuest()) {
+            // The frame which holds the actual PDF content inside the guest
+            content::RenderWidgetHost *guestFrame = webContents->GetRenderViewHost()->GetWidget();
+            guestFrame->AddInputEventObserver(mainRwhv);
+        }
+    }
 }
 
 void RenderWidgetHostViewQt::InitAsChild(gfx::NativeView)
diff --git a/src/core/render_widget_host_view_qt.h b/src/core/render_widget_host_view_qt.h
index aebf59ddb..25fd20115 100644
--- a/src/core/render_widget_host_view_qt.h
+++ b/src/core/render_widget_host_view_qt.h
@@ -21,6 +21,7 @@
 namespace content {
 class RenderFrameHost;
 class RenderWidgetHostImpl;
+class WebContents;
 }
 
 namespace ui {
@@ -30,7 +31,7 @@ class TouchSelectionController;
 namespace QtWebEngineCore {
 
 class RenderWidgetHostViewQtDelegateClient;
-class GuestInputEventObserverQt;
+class InputEventObserverQt;
 class TouchSelectionControllerClientQt;
 class WebContentsAccessibilityQt;
 class WebContentsAdapterClient;
@@ -41,6 +42,7 @@ class RenderWidgetHostViewQt
     , public base::SupportsWeakPtr<RenderWidgetHostViewQt>
     , public content::TextInputManager::Observer
     , public content::RenderFrameMetadataProvider::Observer
+    , public content::RenderWidgetHost::InputEventObserver
 {
 public:
     RenderWidgetHostViewQt(content::RenderWidgetHost* widget);
@@ -51,7 +53,6 @@ public:
     WebContentsAdapterClient *adapterClient() { return m_adapterClient; }
     void setAdapterClient(WebContentsAdapterClient *adapterClient);
     RenderWidgetHostViewQtDelegateClient *delegateClient() const { return m_delegateClient.get(); }
-    void addGuest(content::RenderWidgetHost *);
 
     // Overridden from RenderWidgetHostView:
     void InitAsChild(gfx::NativeView) override;
@@ -149,6 +150,14 @@ public:
     void OnRenderFrameSubmission() override {}
     void OnLocalSurfaceIdChanged(const cc::RenderFrameMetadata &) override {}
 
+    // Overridden from content::RenderWidgetHost::InputEventObserver
+    void OnInputEvent(const blink::WebInputEvent &) override { }
+    void OnInputEventAck(blink::mojom::InputEventResultSource,
+                         blink::mojom::InputEventResultState state,
+                         const blink::WebInputEvent &event) override;
+
+    static void registerInputEventObserver(content::WebContents *, content::RenderFrameHost *);
+
     // Called from RenderWidgetHostViewQtDelegateClient.
     Compositor::Id compositorId();
     void notifyShown();
@@ -185,7 +194,6 @@ private:
     std::unique_ptr<content::CursorManager> m_cursorManager;
 
     ui::FilteredGestureProvider m_gestureProvider;
-    std::unique_ptr<GuestInputEventObserverQt> m_guestInputEventObserver;
 
     viz::FrameSinkId m_frameSinkId;
     std::unique_ptr<RenderWidgetHostViewQtDelegateClient> m_delegateClient;
diff --git a/src/core/web_contents_delegate_qt.cpp b/src/core/web_contents_delegate_qt.cpp
index fd445f88a..b58b56500 100644
--- a/src/core/web_contents_delegate_qt.cpp
+++ b/src/core/web_contents_delegate_qt.cpp
@@ -255,6 +255,10 @@ void WebContentsDelegateQt::RenderFrameCreated(content::RenderFrameHost *render_
 {
     content::FrameTreeNode *node = static_cast<content::RenderFrameHostImpl *>(render_frame_host)->frame_tree_node();
     m_frameFocusedObserver.addNode(node);
+
+    // If it's a child frame (render_widget_host_view_child_frame) install an InputEventObserver on
+    // it. Note that it is only needed for WheelEventAck.
+    RenderWidgetHostViewQt::registerInputEventObserver(web_contents(), render_frame_host);
 }
 
 void WebContentsDelegateQt::PrimaryMainFrameRenderProcessGone(base::TerminationStatus status)