cc: Distinguish single texture mask from normal masks

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 <stddef.h>
 #include <stdint.h>
 
@@ skipping 47 matching lines @@
 // this class.
 class CC_EXPORT Layer : public base::RefCounted<Layer> {
  public:
   using LayerListType = LayerList;
   using LayerIdMap = std::unordered_map<int, scoped_refptr<Layer>>;
 
   enum LayerIdLabels {
     INVALID_ID = -1,
   };
 
+  enum LayerMaskType {
+    NOT_MASK = 0,
+    MULTI_TEXTURE_MASK,
+    SINGLE_TEXTURE_MASK,
+  };
+
   static scoped_refptr<Layer> Create();
 
   int id() const { return inputs_.layer_id; }
 
   Layer* RootLayer();
   Layer* parent() { return parent_; }
   const Layer* parent() const { return parent_; }
   void AddChild(scoped_refptr<Layer> child);
   void InsertChild(scoped_refptr<Layer> child, size_t index);
   void ReplaceChild(Layer* reference, scoped_refptr<Layer> new_layer);
@@ skipping 227 matching lines @@
   // This is only virtual for tests.
   // TODO(awoloszyn): Remove this once we no longer need it for tests
   virtual bool DrawsContent() const;
 
   // This methods typically need to be overwritten by derived classes.
   // TODO(chrishtr): Blink no longer resizes anything during paint. We can
   // remove this.
   virtual void SavePaintProperties();
   // Returns true iff anything was updated that needs to be committed.
   virtual bool Update();
-  virtual void SetIsMask(bool is_mask) {}
+  virtual void SetLayerMaskType(Layer::LayerMaskType type) {}
   virtual bool IsSuitableForGpuRasterization() const;
 
   virtual std::unique_ptr<base::trace_event::ConvertableToTraceFormat>
   TakeDebugInfo();
   virtual void didUpdateMainThreadScrollingReasons();
 
   void SetLayerClient(LayerClient* client) { inputs_.client = client; }
 
   virtual bool IsSnapped();
 
@@ skipping 331 matching lines @@
   // These all act like draw properties, so don't need push properties.
   gfx::Rect visible_layer_rect_;
   size_t num_unclipped_descendants_;
 
   DISALLOW_COPY_AND_ASSIGN(Layer);
 };
 
 }  // namespace cc
 
 #endif  // CC_LAYERS_LAYER_H_