[DevTools] Handle emulated device scale factor and original device scale factor properly.

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 174 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:
+  friend class RenderViewImplScaleFactorTest;
+
   RenderWidgetCompositor(RenderWidgetCompositorDelegate* delegate,
                          CompositorDependencies* compositor_deps);
 
   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_;
   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_