RenderWidgetCompositor should be decoupled from RenderWidget.

content/renderer/gpu/render_widget_compositor.h

 // Copyright (c) 2013 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.
 
 #ifndef CONTENT_RENDERER_GPU_RENDER_WIDGET_COMPOSITOR_H_
 #define CONTENT_RENDERER_GPU_RENDER_WIDGET_COMPOSITOR_H_
 
 #include <stdint.h>
 
 #include "base/callback.h"
@@ skipping 24 matching lines @@
 class Layer;
 class LayerTreeHost;
 
 namespace proto {
 class CompositorMessage;
 }
 
 }
 
 namespace content {
-class RenderWidget;
+
+class RenderWidgetCompositorDelegate;
 
 class CONTENT_EXPORT RenderWidgetCompositor
     : NON_EXPORTED_BASE(public blink::WebLayerTreeView),
       NON_EXPORTED_BASE(public cc::LayerTreeHostClient),
       NON_EXPORTED_BASE(public cc::LayerTreeHostSingleThreadClient),
       NON_EXPORTED_BASE(public cc::RemoteProtoChannel) {
  public:
   // Attempt to construct and initialize a compositor instance for the widget
   // with the given settings. Returns NULL if initialization fails.
   static scoped_ptr<RenderWidgetCompositor> Create(
-      RenderWidget* widget,
+      RenderWidgetCompositorDelegate* delegate,
+      float device_scale_factor,
       CompositorDependencies* compositor_deps);
 
   ~RenderWidgetCompositor() override;
 
   void SetNeverVisible();
   const base::WeakPtr<cc::InputHandler>& GetInputHandler();
   bool BeginMainFrameRequested() const;
   void SetNeedsDisplayOnAllLayers();
   void SetRasterizeOnlyVisibleContent();
   void SetNeedsRedrawRect(gfx::Rect damage_rect);
@@ skipping 110 matching lines @@
   // cc::RemoteProtoChannel implementation.
   void SetProtoReceiver(ProtoReceiver* receiver) override;
   void SendCompositorProto(const cc::proto::CompositorMessage& proto) override;
 
   enum {
     OUTPUT_SURFACE_RETRIES_BEFORE_FALLBACK = 4,
     MAX_OUTPUT_SURFACE_RETRIES = 5,
   };
 
  protected:
-  RenderWidgetCompositor(RenderWidget* widget,
+  RenderWidgetCompositor(RenderWidgetCompositorDelegate* delegate,
                          CompositorDependencies* compositor_deps);
 
-  void Initialize();
+  void Initialize(float device_scale_factor);
   cc::LayerTreeHost* layer_tree_host() { return layer_tree_host_.get(); }
 
  private:
   void LayoutAndUpdateLayers();
   void InvokeLayoutAndPaintCallback();
   bool CompositeIsSynchronous() const;
   void SynchronouslyComposite();
 
   int num_failed_recreate_attempts_;
-  RenderWidget* widget_;
-  CompositorDependencies* compositor_deps_;
+  RenderWidgetCompositorDelegate* const delegate_;
+  CompositorDependencies* const compositor_deps_;
   scoped_ptr<cc::LayerTreeHost> layer_tree_host_;
   bool never_visible_;
 
   blink::WebLayoutAndPaintAsyncCallback* layout_and_paint_async_callback_;
   scoped_ptr<cc::CopyOutputRequest> temporary_copy_output_request_;
 
   cc::RemoteProtoChannel::ProtoReceiver* remote_proto_channel_receiver_;
 
   base::WeakPtrFactory<RenderWidgetCompositor> weak_factory_;
 };
 
 }  // namespace content
 
 #endif  // CONTENT_RENDERER_GPU_RENDER_WIDGET_COMPOSITOR_H_