| Index: content/browser/compositor/software_output_device_mac.h | 
| diff --git a/content/browser/compositor/software_output_device_mac.h b/content/browser/compositor/software_output_device_mac.h | 
| index 5b6ac86b77d56659d23cb4d062fcfe53a441b30a..d97e7aac53706f3ee1eef1792073cc475e739d6c 100644 | 
| --- a/content/browser/compositor/software_output_device_mac.h | 
| +++ b/content/browser/compositor/software_output_device_mac.h | 
| @@ -5,6 +5,9 @@ | 
| #ifndef CONTENT_BROWSER_COMPOSITOR_SOFTWARE_OUTPUT_DEVICE_MAC_H_ | 
| #define CONTENT_BROWSER_COMPOSITOR_SOFTWARE_OUTPUT_DEVICE_MAC_H_ | 
|  | 
| +#include <IOSurface/IOSurface.h> | 
| + | 
| +#include "base/mac/scoped_cftyperef.h" | 
| #include "cc/output/software_output_device.h" | 
|  | 
| namespace gfx { | 
| @@ -22,10 +25,32 @@ class SoftwareOutputDeviceMac : public cc::SoftwareOutputDevice { | 
| explicit SoftwareOutputDeviceMac(ui::Compositor* compositor); | 
| ~SoftwareOutputDeviceMac() override; | 
|  | 
| +  void Resize(const gfx::Size& pixel_size, float scale_factor) override; | 
| +  SkCanvas* BeginPaint(const gfx::Rect& damage_rect) override; | 
| void EndPaint() override; | 
| +  void DiscardBackbuffer() override; | 
| +  void EnsureBackbuffer() override; | 
|  | 
| private: | 
| +  // Copy the pixels from the previous buffer to the new buffer. | 
| +  void CopyPreviousBufferDamage(const gfx::Rect& new_damage_rect); | 
| + | 
| ui::Compositor* compositor_; | 
| +  gfx::Size pixel_size_; | 
| +  float scale_factor_; | 
| + | 
| +  // This surface is double-buffered. The two buffers are in |io_surfaces_|, | 
| +  // and the index of the current buffer is |current_buffer_|. | 
| +  base::ScopedCFTypeRef<IOSurfaceRef> io_surfaces_[2]; | 
| +  int current_index_; | 
| + | 
| +  // The previous frame's damage rectangle. Used to copy unchanged content | 
| +  // between buffers in CopyPreviousBufferDamage. | 
| +  gfx::Rect previous_buffer_damage_rect_; | 
| + | 
| +  // The SkCanvas wrapps the mapped current IOSurface. It is valid only between | 
| +  // BeginPaint and EndPaint. | 
| +  skia::RefPtr<SkCanvas> canvas_; | 
|  | 
| DISALLOW_COPY_AND_ASSIGN(SoftwareOutputDeviceMac); | 
| }; | 
|  |