cc: Move blend_mode to the effect tree

cc/proto/property_tree.proto

 // Copyright 2015 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.
 
 syntax = "proto2";
 
 import "element_id.proto";
 import "rectf.proto";
 import "scroll_offset.proto";
 import "size.proto";
+import "skxfermode.proto";
 import "synced_property.proto";
 import "transform.proto";
 import "vector2df.proto";
 
 option optimize_for = LITE_RUNTIME;
 
 package cc.proto;
 
 // The messages declared in this file correspond to the classes declared in
 // cc/trees/property_tree.h
@@ skipping 58 matching lines @@
   optional int64 target_effect_id = 12;
   optional bool applies_local_clip = 6;
   optional bool layer_clipping_uses_only_local_clip = 7;
   optional bool target_is_clipped = 8;
   optional bool layers_are_clipped = 9;
   optional bool layers_are_clipped_when_surfaces_disabled = 10;
   optional bool resets_clip = 11;
 }
 
 // Proto for struct EffectNodeData.
-// NEXT ID: 25
+// NEXT ID: 26
 message EffectNodeData {
   optional float opacity = 1;
   optional float screen_space_opacity = 2;
+  optional SkXfermode.Mode blend_mode = 25;
   optional bool has_render_surface = 3;
   optional bool has_copy_request = 4;
   optional bool hidden_by_backface_visibility = 14;
   optional bool double_sided = 13;
   optional bool is_drawn = 6;
   optional bool subtree_hidden = 15;
   optional bool has_potential_filter_animation = 21;
   optional bool has_potential_opacity_animation = 7;
   optional bool is_currently_animating_filter = 22;
   optional bool is_currently_animating_opacity = 16;
@@ skipping 115 matching lines @@
   optional int64 sequence_number = 6;
   optional bool is_main_thread = 13;
   optional bool is_active = 14;
   optional bool verify_transform_tree_calculations = 16;
 
   optional Vector2dF inner_viewport_container_bounds_delta = 8;
   optional Vector2dF outer_viewport_container_bounds_delta = 9;
   optional Vector2dF inner_viewport_scroll_bounds_delta = 10;
   repeated int64 always_use_active_tree_opacity_effect_ids = 15 [packed = true];
 }