Chromium implementation of discardBackbuffer WebGraphicsContext3D extension.

webkit/gpu/webgraphicscontext3d_in_process_impl.h

 // Copyright (c) 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 WEBKIT_GPU_WEBGRAPHICSCONTEXT3D_IN_PROCESS_IMPL_H_
 #define WEBKIT_GPU_WEBGRAPHICSCONTEXT3D_IN_PROCESS_IMPL_H_
 
 #include <list>
 #include <set>
 
@@ skipping 90 matching lines @@
       WGC3Dsizei width,
       WGC3Dsizei height,
       WGC3Denum format,
       WGC3Denum type,
       WGC3Denum access);
   virtual void unmapTexSubImage2DCHROMIUM(const void*);
 
   virtual void setVisibilityCHROMIUM(bool visible);
 
   virtual void setMemoryAllocationChangedCallbackCHROMIUM(
-      WebGraphicsMemoryAllocationChangedCallbackCHROMIUM* callback) { }
+      WebGraphicsMemoryAllocationChangedCallbackCHROMIUM* callback);
+
+  virtual void discardFramebufferEXT(WGC3Denum target,
+                                     WGC3Dsizei numAttachments,
+                                     const WGC3Denum* attachments);
+  virtual void ensureFramebufferCHROMIUM();
 
   virtual void copyTextureToParentTextureCHROMIUM(
       WebGLId texture, WebGLId parentTexture);
 
   virtual void rateLimitOffscreenContextCHROMIUM() { }
 
   virtual WebString getRequestableExtensionsCHROMIUM();
   virtual void requestExtensionCHROMIUM(const char*);
 
   virtual void blitFramebufferCHROMIUM(
@@ skipping 419 matching lines @@
   ShaderSourceMap shader_source_map_;
 
   ShHandle fragment_compiler_;
   ShHandle vertex_compiler_;
 };
 
 }  // namespace gpu
 }  // namespace webkit
 
 #endif  // WEBKIT_GPU_WEBGRAPHICSCONTEXT3D_IN_PROCESS_IMPL_H_