Implement filter effects in Core Animation using CAFilters.

ui/gl/ca_renderer_layer_params.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 UI_GL_CA_RENDERER_LAYER_PARAMS_H_
 #define UI_GL_CA_RENDERER_LAYER_PARAMS_H_
 
 #include <vector>
 
 #include "third_party/skia/include/core/SkColor.h"
@@ skipping 51 matching lines @@
     DROP_SHADOW,
     MAX = DROP_SHADOW
   };
   struct GL_EXPORT FilterEffect {
     FilterEffectType type = FilterEffectType::GRAYSCALE;
 
     // For every filter other than DROP_SHADOW, only |amount| is populated.
     float amount = 0;
     gfx::Point drop_shadow_offset;
     SkColor drop_shadow_color = 0;
+
+    bool operator==(const FilterEffect& rhs) const;
   };
   using FilterEffects = std::vector<FilterEffect>;
 
   FilterEffects filter_effects;
 };
 
 }  // namespace ui
 
 #endif  // UI_GL_CA_RENDERER_LAYER_PARAMS_H_