mix-blend-mode implementation for accelerated layers

cc/layers/layer_impl.h

 // Copyright 2011 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_LAYERS_LAYER_IMPL_H_
 #define CC_LAYERS_LAYER_IMPL_H_
 
 #include <set>
 #include <string>
 
@@ skipping 195 matching lines @@
   bool masks_to_bounds() const { return masks_to_bounds_; }
 
   void SetContentsOpaque(bool opaque);
   bool contents_opaque() const { return contents_opaque_; }
 
   void SetOpacity(float opacity);
   float opacity() const { return opacity_; }
   bool OpacityIsAnimating() const;
   bool OpacityIsAnimatingOnImplOnly() const;
 
+  void SetBlendMode(SkXfermode::Mode);
+  SkXfermode::Mode blend_mode() const { return blend_mode_; }
+  bool uses_default_blend_mode() const {
+    return blend_mode_ == SkXfermode::kSrcOver_Mode;
+  }
+
+  void SetIsRootForIsolatedGroup(bool root);
+  bool is_root_for_isolated_group() const {
+    return is_root_for_isolated_group_;
+  }
+
   void SetPosition(gfx::PointF position);
   gfx::PointF position() const { return position_; }
 
   void SetIsContainerForFixedPositionLayers(bool container) {
     is_container_for_fixed_position_layers_ = container;
   }
   // This is a non-trivial function in Layer.
   bool IsContainerForFixedPositionLayers() const {
     return is_container_for_fixed_position_layers_;
   }
@@ skipping 338 matching lines @@
 
   // Whether the "back" of this layer should draw.
   bool double_sided_;
 
   // Tracks if drawing-related properties have changed since last redraw.
   bool layer_property_changed_;
 
   bool masks_to_bounds_;
   bool contents_opaque_;
   float opacity_;
+  SkXfermode::Mode blend_mode_;
+  bool is_root_for_isolated_group_;
   gfx::PointF position_;
   bool preserves_3d_;
   bool use_parent_backface_visibility_;
   bool draw_checkerboard_for_missing_tiles_;
   gfx::Transform sublayer_transform_;
   gfx::Transform transform_;
 
   bool draws_content_;
   bool hide_layer_and_subtree_;
   bool force_render_surface_;
@@ skipping 47 matching lines @@
   // Group of properties that need to be computed based on the layer tree
   // hierarchy before layers can be drawn.
   DrawProperties<LayerImpl> draw_properties_;
 
   DISALLOW_COPY_AND_ASSIGN(LayerImpl);
 };
 
 }  // namespace cc
 
 #endif  // CC_LAYERS_LAYER_IMPL_H_