Oilpan: move 2D Canvas and WebGL objects to the heap.

Source/core/html/canvas/WebGLContextObject.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 10 matching lines @@
  * OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
  * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
  */
 
 #include "config.h"
 
 #include "core/html/canvas/WebGLContextObject.h"
 
 #include "core/html/canvas/WebGLRenderingContextBase.h"
+#include "core/html/canvas/WebGLSharedWebGraphicsContext3D.h"
 
 namespace WebCore {
 
 WebGLContextObject::WebGLContextObject(WebGLRenderingContextBase* context)
     : WebGLObject(context)
     , m_context(context)
+#if ENABLE(OILPAN)
+    , m_sharedWebGraphicsContext3D(context->sharedWebGraphicsContext3D())
+#endif
 {
 }
 
 WebGLContextObject::~WebGLContextObject()

[haraken, 2014/07/15 15:04:56]

Just to confirm: This destructor can drop the last ref to
m_sharedWebGraphicsContext3D. There is no problem in calling DrawingBuffer's
destructor in WebGLContextObject's destructor, right?

[sof, 2014/07/15 16:23:00]

None known - it will happen during the same sweep as that of the
WebGLRenderingContextBase that handles it destruction non-Oilpan.

 {
+#if !ENABLE(OILPAN)
     if (m_context)
         m_context->removeContextObject(this);
+#endif
 }
 
 void WebGLContextObject::detachContext()
 {
     detach();
     if (m_context) {
         deleteObject(m_context->webContext());
         m_context->removeContextObject(this);
-        m_context = 0;
+        m_context = nullptr;
+#if ENABLE(OILPAN)
+        m_sharedWebGraphicsContext3D.clear();
+#endif
     }
 }
 
 blink::WebGraphicsContext3D* WebGLContextObject::getAWebGraphicsContext3D() const
 {
+#if ENABLE(OILPAN)
+    return m_sharedWebGraphicsContext3D ? m_sharedWebGraphicsContext3D->webContext() : 0;
+#else
     return m_context ? m_context->webContext() : 0;
+#endif
+}
+
+void WebGLContextObject::trace(Visitor* visitor)
+{
+    visitor->trace(m_context);
+    WebGLObject::trace(visitor);
 }
 
 }