Implement WEBGL_shared_resources

Source/core/html/canvas/WebGLContextGroup.cpp

Index: Source/core/html/canvas/WebGLContextGroup.cpp
diff --git a/Source/core/html/canvas/WebGLContextGroup.cpp b/Source/core/html/canvas/WebGLContextGroup.cpp
index 46650a6e29205de66c7c84e4b19e1d67f846b9a2..8a6c463fe07bfdf3e84b545f932515767148d247 100644
--- a/Source/core/html/canvas/WebGLContextGroup.cpp
+++ b/Source/core/html/canvas/WebGLContextGroup.cpp
@@ -61,6 +61,12 @@ void WebGLContextGroup::addContext(WebGLRenderingContext* 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();
@@ -96,4 +102,13 @@ void WebGLContextGroup::loseContextGroup(WebGLRenderingContext::LostContextMode
         (*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