Mac: Add partial swap support to NSOpenGLContext path

ui/accelerated_widget_mac/io_surface_texture.h

 // Copyright (c) 2012 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 UI_ACCELERATED_WIDGET_MAC_IO_SURFACE_TEXTURE_H_
 #define UI_ACCELERATED_WIDGET_MAC_IO_SURFACE_TEXTURE_H_
 
 #include <deque>
 #include <list>
 #include <vector>
@@ skipping 22 matching lines @@
 class IOSurfaceContext;
 class RenderWidgetHostViewFrameSubscriber;
 class RenderWidgetHostViewMac;
 
 // This class manages an OpenGL context and IOSurfaceTexture for the accelerated
 // compositing code path. The GL context is attached to
 // RenderWidgetHostViewCocoa for blitting the IOSurfaceTexture.
 class IOSurfaceTexture
     : public base::RefCounted<IOSurfaceTexture> {
  public:
-  // Returns NULL if IOSurfaceTexture or GL API calls fail.
   static scoped_refptr<IOSurfaceTexture> Create(
       bool needs_gl_finish_workaround);
 
   // Set IOSurfaceTexture that will be drawn on the next NSView drawRect.
   bool SetIOSurface(
       IOSurfaceID io_surface_id,
       const gfx::Size& pixel_size) WARN_UNUSED_RESULT;
 
   // Blit the IOSurface to the rectangle specified by |window_rect| in DIPs,
   // with the origin in the lower left corner. If the window rect's size is
   // larger than the IOSurface, the remaining right and bottom edges will be
   // white. |window_scale_factor| is 1 in normal views, 2 in HiDPI views.
   bool DrawIOSurface() WARN_UNUSED_RESULT;
+  bool DrawIOSurfaceWithDamageRect(gfx::Rect damage_rect) WARN_UNUSED_RESULT;
 
   // Returns true if the offscreen context used by this surface has been
   // poisoned.
   bool HasBeenPoisoned() const;
 
  private:
   friend class base::RefCounted<IOSurfaceTexture>;
 
   IOSurfaceTexture(
       const scoped_refptr<IOSurfaceContext>& context,
       bool needs_gl_finish_workaround);
   ~IOSurfaceTexture();
 
+  // Draw the sepecified rect of the IOSurface. If |draw_boundary| is true,
+  // clear any overflow regions with white.
+  bool DrawIOSurfaceInternal(gfx::Rect damage_rect, bool draw_boundary);
+
   // Unref the IOSurfaceTexture and delete the associated GL texture. If the GPU
   // process is no longer referencing it, this will delete the IOSurface.
   void ReleaseIOSurfaceAndTexture();
 
   // Check for GL errors and store the result in error_. Only return new
   // errors
   GLenum GetAndSaveGLError();
 
   // Offscreen context used for all operations other than drawing to the
   // screen. This is in the same share group as the contexts used for
@@ skipping 32 matching lines @@
 
   static void EvictionScheduleDoEvict();
   static void EvictionDoEvict();
   static base::LazyInstance<EvictionQueue> eviction_queue_;
   static bool eviction_scheduled_;
 };
 
 }  // namespace ui
 
 #endif  // UI_ACCELERATED_WIDGET_MAC_IO_SURFACE_TEXTURE_H_