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 06204706c6c00ec9d79b816b717341f21eef9006..2603c1bb82e8ac18f324749b4ac291fe22dab325 100644
--- a/Source/core/html/canvas/WebGLContextGroup.cpp
+++ b/Source/core/html/canvas/WebGLContextGroup.cpp
@@ -39,6 +39,8 @@ PassRefPtr<WebGLContextGroup> WebGLContextGroup::create()
 }
 
 WebGLContextGroup::WebGLContextGroup()
+    : m_contextCreationCount(0)
+    , m_acquireRequestCount(0)
 {
 }
 
@@ -54,13 +56,19 @@ GraphicsContext3D* WebGLContextGroup::getAGraphicsContext3D()
     return (*it)->graphicsContext3D();
 }
 
-void WebGLContextGroup::addContext(WebGLRenderingContext* context)
+unsigned WebGLContextGroup::addContext(WebGLRenderingContext* context)
 {
     m_contexts.add(context);
+    return m_contextCreationCount++;
 }
 
 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);
+    }
+
     // We must call detachAndRemoveAllObjects before removing the last context.
     if (m_contexts.size() == 1 && m_contexts.contains(context))
         detachAndRemoveAllObjects();
@@ -94,4 +102,18 @@ void WebGLContextGroup::loseContextGroup(WebGLRenderingContext::LostContextMode
     detachAndRemoveAllObjects();
 }
 
+long WebGLContextGroup::generateAcquireRequestId()
+{
+    return ++m_acquireRequestCount;
+}
+
+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