Revert 151153 - Partial revert of 146621

ui/compositor/layer.h

Index: ui/compositor/layer.h
===================================================================
--- ui/compositor/layer.h	(revision 151158)
+++ ui/compositor/layer.h	(working copy)
@@ -13,6 +13,7 @@
 #include "base/memory/scoped_ptr.h"
 #include "base/message_loop.h"
 #include "third_party/WebKit/Source/Platform/chromium/public/WebContentLayerClient.h"
+#include "third_party/WebKit/Source/Platform/chromium/public/WebExternalTextureLayerClient.h"
 #include "third_party/WebKit/Source/Platform/chromium/public/WebLayer.h"
 #include "third_party/skia/include/core/SkColor.h"
 #include "third_party/skia/include/core/SkRegion.h"
@@ -43,7 +44,8 @@
 // NULL, but the children are not deleted.
 class COMPOSITOR_EXPORT Layer
     : public LayerAnimationDelegate,
-      NON_EXPORTED_BASE(public WebKit::WebContentLayerClient) {
+      NON_EXPORTED_BASE(public WebKit::WebContentLayerClient),
+      NON_EXPORTED_BASE(public WebKit::WebExternalTextureLayerClient) {
  public:
   Layer();
   explicit Layer(LayerType type);
@@ -260,6 +262,11 @@
 
   WebKit::WebLayer web_layer() { return web_layer_; }
 
+  // WebExternalTextureLayerClient
+  virtual unsigned prepareTexture(
+      WebKit::WebTextureUpdater& /* updater */) OVERRIDE;
+  virtual WebKit::WebGraphicsContext3D* context() OVERRIDE;
+
   float device_scale_factor() const { return device_scale_factor_; }
 
   // Forces a render surface to be used on this layer. This has no positive