[Do not submit] D3DKMTWaitForVerticalBlankEvent VSync prototype

content/browser/compositor/browser_compositor_output_surface.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_BROWSER_COMPOSITOR_BROWSER_COMPOSITOR_OUTPUT_SURFACE_H_
 #define CONTENT_BROWSER_COMPOSITOR_BROWSER_COMPOSITOR_OUTPUT_SURFACE_H_
 
 #include "base/macros.h"
 #include "base/threading/non_thread_safe.h"
 #include "build/build_config.h"
 #include "cc/output/output_surface.h"
 #include "content/common/content_export.h"
 
 namespace cc {
 class SoftwareOutputDevice;
 }
 
 namespace display_compositor {
 class CompositorOverlayCandidateValidator;
 }
 
 namespace gfx {
 enum class SwapResult;
 }
 
 namespace content {
 class ReflectorImpl;
+class GpuVSyncControl;
 
 class CONTENT_EXPORT BrowserCompositorOutputSurface
     : public cc::OutputSurface {
  public:
   using UpdateVSyncParametersCallback =
       base::Callback<void(base::TimeTicks timebase, base::TimeDelta interval)>;
 
   ~BrowserCompositorOutputSurface() override;
 
   // cc::OutputSurface implementation.
   cc::OverlayCandidateValidator* GetOverlayCandidateValidator() const override;
   bool HasExternalStencilTest() const override;
   void ApplyExternalStencil() override;
 
   void SetReflector(ReflectorImpl* reflector);
 
   // Called when |reflector_| was updated.
   virtual void OnReflectorChanged();
 
+  // Called to determine if this type of OutputSurface provides GPU VSync.
+  virtual GpuVSyncControl* GetVSyncControl();
+
 #if defined(OS_MACOSX)
   virtual void SetSurfaceSuspendedForRecycle(bool suspended) = 0;
 #endif
 
  protected:
   // Constructor used by the accelerated implementation.
   BrowserCompositorOutputSurface(
       scoped_refptr<cc::ContextProvider> context,
       const UpdateVSyncParametersCallback& update_vsync_parameters_callback,
       std::unique_ptr<display_compositor::CompositorOverlayCandidateValidator>
@@ skipping 15 matching lines @@
  private:
   std::unique_ptr<display_compositor::CompositorOverlayCandidateValidator>
       overlay_candidate_validator_;
 
   DISALLOW_COPY_AND_ASSIGN(BrowserCompositorOutputSurface);
 };
 
 }  // namespace content
 
 #endif  // CONTENT_BROWSER_COMPOSITOR_BROWSER_COMPOSITOR_OUTPUT_SURFACE_H_