mix-blend-mode implementation for accelerated layers

cc/layers/layer.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_LAYERS_LAYER_H_
 #define CC_LAYERS_LAYER_H_
 
 #include <set>
 #include <string>
 
@@ skipping 11 matching lines @@
 #include "cc/layers/layer_lists.h"
 #include "cc/layers/layer_position_constraint.h"
 #include "cc/layers/paint_properties.h"
 #include "cc/layers/render_surface.h"
 #include "cc/output/filter_operations.h"
 #include "cc/trees/occlusion_tracker.h"
 #include "skia/ext/refptr.h"
 #include "third_party/skia/include/core/SkColor.h"
 #include "third_party/skia/include/core/SkImageFilter.h"
 #include "third_party/skia/include/core/SkPicture.h"
+#include "third_party/skia/include/core/SkXfermode.h"
 #include "ui/gfx/rect.h"
 #include "ui/gfx/rect_f.h"
 #include "ui/gfx/transform.h"
 
 namespace gfx {
 class BoxF;
 }
 
 namespace cc {
 
@@ skipping 77 matching lines @@
   const Layer* mask_layer() const { return mask_layer_.get(); }
 
   virtual void SetNeedsDisplayRect(const gfx::RectF& dirty_rect);
   void SetNeedsDisplay() { SetNeedsDisplayRect(gfx::RectF(bounds())); }
 
   void SetOpacity(float opacity);
   float opacity() const { return opacity_; }
   bool OpacityIsAnimating() const;
   virtual bool OpacityCanAnimateOnImplThread() const;
 
+  void SetBlendMode(SkXfermode::Mode blend_mode);
+  SkXfermode::Mode blend_mode() const { return blend_mode_; }
+
+  bool uses_default_blend_mode() const {
+    return blend_mode_ == SkXfermode::kSrcOver_Mode;
+  }
+
+  // A layer is root for an isolated group when it and all its descendants are
+  // drawn over a black and fully transparent background, creating an isolated
+  // group. It should be used along with SetBlendMode(), in order to restrict
+  // layers within the group to blend with layers outside this group.
+  void SetIsRootForIsolatedGroup(bool root);
+  bool is_root_for_isolated_group() const {
+    return is_root_for_isolated_group_;
+  }
+
   void SetFilters(const FilterOperations& filters);
   const FilterOperations& filters() const { return filters_; }
   bool FilterIsAnimating() const;
 
   // Background filters are filters applied to what is behind this layer, when
   // they are viewed through non-opaque regions in this layer. They are used
   // through the WebLayer interface, and are not exposed to HTML.
   void SetBackgroundFilters(const FilterOperations& filters);
   const FilterOperations& background_filters() const {
     return background_filters_;
@@ skipping 313 matching lines @@
   void SetNeedsCommit();
   // Called when there's been a change in layer structure.  Implies both
   // SetNeedsUpdate and SetNeedsCommit, but not SetNeedsPushProperties.
   void SetNeedsFullTreeSync();
 
   // Called when the next commit should wait until the pending tree is activated
   // before finishing the commit and unblocking the main thread. Used to ensure
   // unused resources on the impl thread are returned before commit completes.
   void SetNextCommitWaitsForActivation();
 
+  // Called when the blend mode or filters have been changed.
+  void SetNeedsFilterContextIfNeeded();
+
   void SetNeedsPushProperties();
   void AddDependentNeedsPushProperties();
   void RemoveDependentNeedsPushProperties();
   bool parent_should_know_need_push_properties() const {
     return needs_push_properties() || descendant_needs_push_properties();
   }
 
   bool IsPropertyChangeAllowed() const;
 
   // If this layer has a scroll parent, it removes |this| from its list of
@@ skipping 73 matching lines @@
   bool have_wheel_event_handlers_;
   bool user_scrollable_horizontal_;
   bool user_scrollable_vertical_;
   Region non_fast_scrollable_region_;
   Region touch_event_handler_region_;
   gfx::PointF position_;
   gfx::PointF anchor_point_;
   SkColor background_color_;
   CompositingReasons compositing_reasons_;
   float opacity_;
+  SkXfermode::Mode blend_mode_;
+  bool is_root_for_isolated_group_;
   FilterOperations filters_;
   FilterOperations background_filters_;
   float anchor_point_z_;
   bool is_container_for_fixed_position_layers_;
   LayerPositionConstraint position_constraint_;
   bool is_drawable_;
   bool hide_layer_and_subtree_;
   bool masks_to_bounds_;
   bool contents_opaque_;
   bool double_sided_;
@@ skipping 25 matching lines @@
   DrawProperties<Layer> draw_properties_;
 
   PaintProperties paint_properties_;
 
   DISALLOW_COPY_AND_ASSIGN(Layer);
 };
 
 }  // namespace cc
 
 #endif  // CC_LAYERS_LAYER_H_