cc: Move blend_mode to the effect tree

cc/trees/effect_node.h

 // Copyright 2016 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_TREES_EFFECT_NODE_H_
 #define CC_TREES_EFFECT_NODE_H_
 
 #include "cc/base/cc_export.h"
 #include "cc/output/filter_operations.h"
+#include "third_party/skia/include/core/SkXfermode.h"
 
 namespace base {
 namespace trace_event {
 class TracedValue;
 }  // namespace trace_event
 }  // namespace base
 
 namespace cc {
 
 class RenderSurfaceImpl;
 
 namespace proto {
 class TreeNode;
 }  // namespace proto
 
 struct CC_EXPORT EffectNode {
   EffectNode();
   EffectNode(const EffectNode& other);
 
   int id;
   int parent_id;
   int owner_id;
 
   float opacity;
   float screen_space_opacity;
 
   FilterOperations filters;
   FilterOperations background_filters;
 
+  SkXfermode::Mode blend_mode;
+
   gfx::Vector2dF surface_contents_scale;
 
   bool has_render_surface;
   RenderSurfaceImpl* render_surface;
   bool has_copy_request;
   bool hidden_by_backface_visibility;
   bool double_sided;
   bool is_drawn;
   // TODO(jaydasika) : Delete this after implementation of
   // SetHideLayerAndSubtree is cleaned up. (crbug.com/595843)
@@ skipping 18 matching lines @@
   bool operator==(const EffectNode& other) const;
 
   void ToProtobuf(proto::TreeNode* proto) const;
   void FromProtobuf(const proto::TreeNode& proto);
   void AsValueInto(base::trace_event::TracedValue* value) const;
 };
 
 }  // namespace cc
 
 #endif  // CC_TREES_EFFECT_NODE_H_