Add a command-line flag to set GPU rasterization multisampling.

content/test/fake_compositor_dependencies.h

 // Copyright 2014 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_TEST_FAKE_COMPOSITOR_DEPENDENCIES_H__
 #define CONTENT_TEST_FAKE_COMPOSITOR_DEPENDENCIES_H__
 
 #include "cc/test/test_gpu_memory_buffer_manager.h"
 #include "cc/test/test_shared_bitmap_manager.h"
 #include "content/renderer/gpu/compositor_dependencies.h"
 #include "content/test/fake_renderer_scheduler.h"
 
 namespace content {
 
 class FakeCompositorDependencies : public CompositorDependencies {
  public:
   FakeCompositorDependencies();
 
   // CompositorDependencies implementation.
   bool IsImplSidePaintingEnabled() override;
   bool IsGpuRasterizationForced() override;
   bool IsGpuRasterizationEnabled() override;
+  int GpuRasterizationMSAASampleCount() override;
   bool IsLcdTextEnabled() override;
   bool IsDistanceFieldTextEnabled() override;
   bool IsZeroCopyEnabled() override;
   bool IsOneCopyEnabled() override;
   bool IsElasticOverscrollEnabled() override;
   uint32 GetImageTextureTarget() override;
   scoped_refptr<base::SingleThreadTaskRunner>
   GetCompositorMainThreadTaskRunner() override;
   scoped_refptr<base::SingleThreadTaskRunner>
   GetCompositorImplThreadTaskRunner() override;
   cc::SharedBitmapManager* GetSharedBitmapManager() override;
   gpu::GpuMemoryBufferManager* GetGpuMemoryBufferManager() override;
   RendererScheduler* GetRendererScheduler() override;
   cc::ContextProvider* GetSharedMainThreadContextProvider() override;
   scoped_ptr<cc::BeginFrameSource> CreateExternalBeginFrameSource(
       int routing_id) override;
 
  private:
   cc::TestSharedBitmapManager shared_bitmap_manager_;
   cc::TestGpuMemoryBufferManager gpu_memory_buffer_manager_;
   FakeRendererScheduler renderer_scheduler_;
 
   DISALLOW_COPY_AND_ASSIGN(FakeCompositorDependencies);
 };
 
 }  // namespace content
 
 #endif  // CONTENT_TEST_FAKE_COMPOSITOR_DEPENDENCIES_H__