Accelerate the lighten blendmode if GL_EXT_blend_minmax is enabled.

cc/output/gl_renderer.h

 // Copyright 2010 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 CC_OUTPUT_GL_RENDERER_H_
 #define CC_OUTPUT_GL_RENDERER_H_
 
 #include "base/cancelable_callback.h"
 #include "cc/base/cc_export.h"
 #include "cc/base/scoped_ptr_deque.h"
@@ skipping 125 matching lines @@
  private:
   friend class GLRendererShaderPixelTest;
   friend class GLRendererShaderTest;
 
   static void ToGLMatrix(float* gl_matrix, const gfx::Transform& transform);
 
   void DrawCheckerboardQuad(const DrawingFrame* frame,
                             const CheckerboardDrawQuad* quad);
   void DrawDebugBorderQuad(const DrawingFrame* frame,
                            const DebugBorderDrawQuad* quad);
-  static bool ShouldApplyBlendModeUsingBlendFunc(const DrawQuad* quad);
-  void ApplyBlendModeUsingBlendFunc(const DrawQuad* quad);
-  void RestoreBlendFuncToDefault();
+  static bool IsDefaultBlendMode(SkXfermode::Mode blend_mode) {
+    return blend_mode == SkXfermode::kSrcOver_Mode;
+  }
+  bool CanApplyBlendModeUsingBlendFunc(SkXfermode::Mode blend_mode);
+  void ApplyBlendModeUsingBlendFunc(SkXfermode::Mode blend_mode);
+  void RestoreBlendFuncToDefault(SkXfermode::Mode blend_mode);
 
   gfx::Rect GetBackdropBoundingBoxForRenderPassQuad(
       DrawingFrame* frame,
       const RenderPassDrawQuad* quad,
       const gfx::Transform& contents_device_transform);
   scoped_ptr<ScopedResource> GetBackdropTexture(const gfx::Rect& bounding_rect);
 
   static bool ShouldApplyBackgroundFilters(DrawingFrame* frame,
                                            const RenderPassDrawQuad* quad);
   skia::RefPtr<SkImage> ApplyBackgroundFilters(
@@ skipping 270 matching lines @@
   struct PendingAsyncReadPixels;
   ScopedPtrVector<PendingAsyncReadPixels> pending_async_read_pixels_;
 
   scoped_ptr<ResourceProvider::ScopedWriteLockGL> current_framebuffer_lock_;
 
   class SyncQuery;
   ScopedPtrDeque<SyncQuery> pending_sync_queries_;
   ScopedPtrDeque<SyncQuery> available_sync_queries_;
   scoped_ptr<SyncQuery> current_sync_query_;
   bool use_sync_query_;
+  bool use_blend_minmax;

[piman, 2014/10/09 22:32:15]

drive-by nit: use_blend_minmax_

 
   SkBitmap on_demand_tile_raster_bitmap_;
   ResourceProvider::ResourceId on_demand_tile_raster_resource_id_;
 
   DISALLOW_COPY_AND_ASSIGN(GLRenderer);
 };
 
 // Setting DEBUG_GL_CALLS to 1 will call glGetError() after almost every GL
 // call made by the compositor. Useful for debugging rendering issues but
 // will significantly degrade performance.
 #define DEBUG_GL_CALLS 0
 
 #if DEBUG_GL_CALLS && !defined(NDEBUG)
 #define GLC(context, x)                                                        \
   (x, GLRenderer::DebugGLCall(&* context, #x, __FILE__, __LINE__))
 #else
 #define GLC(context, x) (x)
 #endif
 
 }  // namespace cc
 
 #endif  // CC_OUTPUT_GL_RENDERER_H_