Adding support for per vertex opacity on textured layer

cc/texture_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_TEXTURE_LAYER_H_
 #define CC_TEXTURE_LAYER_H_
 
 #include "cc/cc_export.h"
 #include "cc/layer.h"
 
@@ skipping 16 matching lines @@
     void clearClient() { m_client = 0; }
 
     virtual scoped_ptr<LayerImpl> createLayerImpl(LayerTreeImpl* treeImpl) OVERRIDE;
 
     // Sets whether this texture should be Y-flipped at draw time. Defaults to true.
     void setFlipped(bool);
 
     // Sets a UV transform to be used at draw time. Defaults to (0, 0, 1, 1).
     void setUVRect(const gfx::RectF&);
 
+    // Sets an opacity value per vertex. It will be multiplied by the layer opacity value.
+    void setVertexOpacity(float bottomLeft, float topLeft, float topRight, float bottomRight);
+
     // Sets whether the alpha channel is premultiplied or unpremultiplied. Defaults to true.
     void setPremultipliedAlpha(bool);
 
     // Sets whether this context should rate limit on damage to prevent too many frames from
     // being queued up before the compositor gets a chance to run. Requires a non-nil client.
     // Defaults to false.
     void setRateLimitContext(bool);
 
     // Code path for plugins which supply their own texture ID.
     void setTextureId(unsigned);
@@ skipping 10 matching lines @@
 
 protected:
     explicit TextureLayer(TextureLayerClient*);
     virtual ~TextureLayer();
 
 private:
     TextureLayerClient* m_client;
 
     bool m_flipped;
     gfx::RectF m_uvRect;
+    // [bottom left, top left, top right, bottom right]
+    float m_vertexOpacity[4];
     bool m_premultipliedAlpha;
     bool m_rateLimitContext;
     bool m_contextLost;
     bool m_contentCommitted;
 
     unsigned m_textureId;
 };
 
 }
 #endif  // CC_TEXTURE_LAYER_H_