Implement WEBGL_shared_resources

Source/core/html/canvas/WebGLContextGroup.cpp

 /*
  * Copyright (C) 2011 Apple 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
  *    notice, this list of conditions and the following disclaimer in the
@@ skipping 43 matching lines @@
     return (*it)->graphicsContext3D();
 }
 
 void WebGLContextGroup::addContext(WebGLRenderingContext* context)
 {
     m_contexts.add(context);
 }
 
 void WebGLContextGroup::removeContext(WebGLRenderingContext* context)
 {
+    // Release all the resources this context has acquired.
+    for (HashSet<WebGLSharedObject*>::iterator it = m_groupObjects.begin(); it != m_groupObjects.end(); ++it) {
+        (*it)->release(context);
+        (*it)->cancelAllPendingRequestsForContext(context);
+    }
+
     // We must call detachAndRemoveAllObjects before removing the last context.
     if (m_contexts.size() == 1 && m_contexts.contains(context))
         detachAndRemoveAllObjects();
 
     m_contexts.remove(context);
 }
 
 void WebGLContextGroup::removeObject(WebGLSharedObject* object)
 {
     m_groupObjects.remove(object);
@@ skipping 15 matching lines @@
 void WebGLContextGroup::loseContextGroup(WebGLRenderingContext::LostContextMode mode)
 {
     // Detach must happen before loseContextImpl, which destroys the GraphicsContext3D
     // and prevents groupObjects from being properly deleted.
     detachAndRemoveAllObjects();
 
     for (HashSet<WebGLRenderingContext*>::iterator it = m_contexts.begin(); it != m_contexts.end(); ++it)
         (*it)->loseContextImpl(mode);
 }
 
+void WebGLContextGroup::cancelAcquireSharedResource(const WebGLRenderingContext* context, long id)
+{
+    for (HashSet<WebGLSharedObject*>::iterator it = m_groupObjects.begin(); it != m_groupObjects.end(); ++it) {
+        if ((*it)->cancelAcquireRequest(context, id)) {
+            break;
+        }
+    }
+}
+
 } // namespace WebCore