Oilpan: extend tracing over WebFrame trees.

Source/web/WebFrame.cpp

 // Copyright 2014 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "config.h"
 #include "public/web/WebFrame.h"
 
 #include "core/frame/RemoteFrame.h"
 #include "core/html/HTMLFrameOwnerElement.h"
 #include "platform/UserGestureIndicator.h"
@@ skipping 208 matching lines @@
     , m_opener(0)
     , m_openedFrameTracker(new OpenedFrameTracker)
 {
 }
 
 WebFrame::~WebFrame()
 {
     m_openedFrameTracker.reset(0);
 }
 
-void WebFrame::traceChildren(Visitor* visitor, WebFrame* frame)
+#if ENABLE(OILPAN)
+void WebFrame::traceFrame(Visitor* visitor, WebFrame* frame)
 {
-#if ENABLE(OILPAN)
-    // Trace the children frames.
-    WebFrame* child = frame ? frame->firstChild() : 0;
-    while (child) {
-        if (child->isWebLocalFrame())
-            visitor->trace(toWebLocalFrameImpl(child));
-        else
-            visitor->trace(toWebRemoteFrameImpl(child));
+    if (!frame)
+        return;
 
-        child = child->nextSibling();
-    }
-#endif
+    if (frame->isWebLocalFrame())
+        visitor->trace(toWebLocalFrameImpl(frame));
+    else
+        visitor->trace(toWebRemoteFrameImpl(frame));
 }
 
+void WebFrame::traceFrames(Visitor* visitor, WebFrame* frame)
+{
+    ASSERT(frame);
+    traceFrame(visitor, frame->m_parent);
+    for (WebFrame* child = frame->firstChild(); child; child = child->nextSibling())
+        traceFrame(visitor, child);
+    // m_opener is a weak reference.
+    frame->m_openedFrameTracker->traceFrames(visitor);
+}
+
+bool WebFrame::isAlive(Visitor* visitor, WebFrame* frame)
+{
+    if (!frame)
+        return true;
+
+    if (frame->isWebLocalFrame())
+        return visitor->isAlive(toWebLocalFrameImpl(frame));
+
+    return visitor->isAlive(toWebRemoteFrameImpl(frame));
+}
+
+void WebFrame::clearWeakFrames(Visitor* visitor)
+{
+    if (!isAlive(visitor, m_opener))
+        m_opener = nullptr;
+}
+#endif
+
 } // namespace blink