Allow ownership passing of the Callback pointer for signalSyncPoint.

Source/Platform/chromium/public/WebGraphicsContext3D.h

 /*
  * Copyright (C) 2012 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:
  *
  *     * Redistributions of source code must retain the above copyright
  * notice, this list of conditions and the following disclaimer.
  *     * Redistributions in binary form must reproduce the above
@@ skipping 129 matching lines @@
     class WebGraphicsMemoryAllocationChangedCallbackCHROMIUM {
     public:
         virtual void onMemoryAllocationChanged(WebGraphicsMemoryAllocation) = 0;
 
     protected:
         virtual ~WebGraphicsMemoryAllocationChangedCallbackCHROMIUM() { }
     };
 
     class WebGraphicsSyncPointCallback {
     public:
+        virtual ~WebGraphicsSyncPointCallback() { }
+
         virtual void onSyncPointReached() = 0;
-
-    protected:
-        virtual ~WebGraphicsSyncPointCallback() { }
     };
 
     // This destructor needs to be public so that using classes can destroy instances if initialization fails.
     virtual ~WebGraphicsContext3D() { }
 
     // Makes the OpenGL context current on the current thread. Returns true on
     // success.
     virtual bool makeContextCurrent() = 0;
 
     // The size of the region into which this WebGraphicsContext3D is rendering.
@@ skipping 18 matching lines @@
     virtual void discardBackbufferCHROMIUM() { }
     virtual void ensureBackbufferCHROMIUM() { }
 
     // Query whether it is built on top of compliant GLES2 implementation.
     virtual bool isGLES2Compliant() = 0;
 
     virtual bool setParentContext(WebGraphicsContext3D* parentContext) { return false; }
 
     virtual unsigned insertSyncPoint() { return 0; }
     virtual void waitSyncPoint(unsigned) { }
-    virtual void signalSyncPoint(unsigned syncPoint, WebGraphicsSyncPointCallback*) { }
+    // This call passes ownership of the WebGraphicsSyncPointCallback to the
+    // WebGraphicsContext3D implementation.
+    virtual void signalSyncPoint(unsigned syncPoint, WebGraphicsSyncPointCallback* callback) { delete callback; }
 
     // Helper for software compositing path. Reads back the frame buffer into
     // the memory region pointed to by "pixels" with size "bufferSize". It is
     // expected that the storage for "pixels" covers (4 * width * height) bytes.
     // The RGBA channels are packed into "pixels" using SkBitmap's byte
     // ordering. Returns true on success.
     virtual bool readBackFramebuffer(unsigned char* pixels, size_t bufferSize, WebGLId framebuffer, int width, int height) = 0;
 
     // Returns the id of the texture which is used for storing the contents of
     // the framebuffer associated with this context. This texture is accessible
@@ skipping 290 matching lines @@
     virtual void imageBufferDataCHROMIUM(WGC3Denum target, WGC3Dsizei width, WGC3Dsizei height) { }
 
 protected:
     virtual GrGLInterface* onCreateGrGLInterface() { return 0; }
 
 };
 
 } // namespace WebKit
 
 #endif