Delete dead invalidate function.

sky/engine/public/platform/WebLayer.h

 /*
  * Copyright (C) 2011 Google Inc. All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions
  * are met:
  *
  * 1.  Redistributions of source code must retain the above copyright
  *     notice, this list of conditions and the following disclaimer.
  * 2.  Redistributions in binary form must reproduce the above copyright
@@ skipping 37 matching lines @@
 struct WebFloatRect;
 struct WebLayerPositionConstraint;
 
 class WebLayer {
 public:
     virtual ~WebLayer() { }
 
     // Returns a positive ID that will be unique across all WebLayers allocated in this process.
     virtual int id() const = 0;
 
-    // Sets the entire layer as invalid, i.e. needs to update its content.
-    virtual void invalidate() = 0;
-
     // These functions do not take ownership of the WebLayer* parameter.
     virtual void addChild(WebLayer*) = 0;
     virtual void insertChild(WebLayer*, size_t index) = 0;
     virtual void replaceChild(WebLayer* reference, WebLayer* newLayer) = 0;
     virtual void removeFromParent() = 0;
     virtual void removeAllChildren() = 0;
 
     virtual void setBounds(const WebSize&) = 0;
     virtual WebSize bounds() const = 0;
 
@@ skipping 100 matching lines @@
     // so, but this is to facilitate benchmarks and tests.
     virtual void setForceRenderSurface(bool) = 0;
 
     // True if the layer is not part of a tree attached to a WebLayerTreeView.
     virtual bool isOrphan() const = 0;
 };
 
 } // namespace blink
 
 #endif  // SKY_ENGINE_PUBLIC_PLATFORM_WEBLAYER_H_