cc: Allow changing mask type when pushing properties.

cc/layers/picture_layer_impl.h

 // Copyright 2012 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_PICTURE_LAYER_IMPL_H_
 #define CC_LAYERS_PICTURE_LAYER_IMPL_H_
 
 #include <stddef.h>
 
 #include <map>
@@ skipping 20 matching lines @@
     : public LayerImpl,
       NON_EXPORTED_BASE(public PictureLayerTilingClient) {
  public:
   static std::unique_ptr<PictureLayerImpl>
   Create(LayerTreeImpl* tree_impl, int id, Layer::LayerMaskType mask_type) {
     return base::WrapUnique(new PictureLayerImpl(tree_impl, id, mask_type));
   }
   ~PictureLayerImpl() override;
 
   Layer::LayerMaskType mask_type() const { return mask_type_; }
+  void SetLayerMaskType(Layer::LayerMaskType type);
 
   // LayerImpl overrides.
   const char* LayerTypeAsString() const override;
   std::unique_ptr<LayerImpl> CreateLayerImpl(LayerTreeImpl* tree_impl) override;
   void PushPropertiesTo(LayerImpl* layer) override;
   void AppendQuads(RenderPass* render_pass,
                    AppendQuadsData* append_quads_data) override;
   void NotifyTileStateChanged(const Tile* tile) override;
   void ResetRasterScale();
   void DidBeginTracing() override;
@@ skipping 92 matching lines @@
   float ideal_contents_scale_;
 
   float raster_page_scale_;
   float raster_device_scale_;
   float raster_source_scale_;
   float raster_contents_scale_;
   float low_res_raster_contents_scale_;
 
   bool was_screen_space_transform_animating_;
   bool only_used_low_res_last_append_quads_;
-  const Layer::LayerMaskType mask_type_;
+  Layer::LayerMaskType mask_type_;
 
   bool nearest_neighbor_;
   bool use_transformed_rasterization_;
   bool is_directly_composited_image_;
 
   // Use this instead of |visible_layer_rect()| for tiling calculations. This
   // takes external viewport and transform for tile priority into account.
   gfx::Rect viewport_rect_for_tile_priority_in_content_space_;
 
   gfx::Size gpu_raster_max_texture_size_;
 
   // List of tilings that were used last time we appended quads. This can be
   // used as an optimization not to remove tilings if they are still being
   // drawn. Note that accessing this vector should only be done in the context
   // of comparing pointers, since objects pointed to are not guaranteed to
   // exist.
   std::vector<PictureLayerTiling*> last_append_quads_tilings_;
 
   DISALLOW_COPY_AND_ASSIGN(PictureLayerImpl);
 };
 
 }  // namespace cc
 
 #endif  // CC_LAYERS_PICTURE_LAYER_IMPL_H_