Set device scale factor in CompositorFrame and scale frame size in WS.

services/ui/ws/frame_generator.h

 // 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.
 
 #ifndef SERVICES_UI_WS_FRAME_GENERATOR_H_
 #define SERVICES_UI_WS_FRAME_GENERATOR_H_
 
 #include <memory>
 #include <unordered_map>
 #include <vector>
@@ skipping 28 matching lines @@
 class ServerWindow;
 
 // Responsible for redrawing the display in response to the redraw requests by
 // submitting CompositorFrames to the owned CompositorFrameSink.
 class FrameGenerator : public ServerWindowTracker,
                        public cc::mojom::MojoCompositorFrameSinkClient {
  public:
   FrameGenerator(FrameGeneratorDelegate* delegate, ServerWindow* root_window);
   ~FrameGenerator() override;
 
+  void set_device_scale_factor(float device_scale_factor) {
+    device_scale_factor_ = device_scale_factor;
+  }
+
   // Schedules a redraw for the provided region.
   void OnAcceleratedWidgetAvailable(gfx::AcceleratedWidget widget);
 
   // Adds a reference to new surface with |surface_id| for |window|. This
   // reference is to ensure the surface is not deleted while it's still being
   // displayed. The display root surface has a reference from the top level
   // root. All child surfaces are embedded by the display root and receive a
   // reference from it.
   //
   // If a new display root Surface is created, then all child surfaces will
@@ skipping 52 matching lines @@
   // Removes all retained references to surfaces.
   void RemoveAllSurfaceReferences();
 
   cc::mojom::DisplayCompositor* GetDisplayCompositor();
 
   // ServerWindowObserver implementation.
   void OnWindowDestroying(ServerWindow* window) override;
 
   FrameGeneratorDelegate* delegate_;
   ServerWindow* const root_window_;
+  float device_scale_factor_;

[Fady Samuel, 2016/12/15 18:27:51]

drive-by: Initialize this maybe to 1.0f?

[riajiang, 2016/12/15 19:01:43]

Done.

 
   gfx::Size last_submitted_frame_size_;
   cc::LocalFrameId local_frame_id_;
   cc::SurfaceIdAllocator id_allocator_;
   cc::mojom::MojoCompositorFrameSinkPtr compositor_frame_sink_;
 
   // Active references held by this client to surfaces that could be embedded in
   // a CompositorFrame submitted from FrameGenerator.
   std::unordered_map<cc::FrameSinkId, cc::SurfaceReference, cc::FrameSinkIdHash>
       active_references_;
@@ skipping 17 matching lines @@
   base::WeakPtrFactory<FrameGenerator> weak_factory_;
 
   DISALLOW_COPY_AND_ASSIGN(FrameGenerator);
 };
 
 }  // namespace ws
 
 }  // namespace ui
 
 #endif  // SERVICES_UI_WS_FRAME_GENERATOR_H_