Added UseCounter for clearing browsing context name on cross-origin name

third_party/WebKit/Source/core/page/FrameTree.cpp

 /*
  * Copyright (C) Research In Motion Limited 2010. All rights reserved.
  * Copyright (C) 2006 Apple Computer, Inc.
  *
  * This library is free software; you can redistribute it and/or
  * modify it under the terms of the GNU Library General Public
  * License as published by the Free Software Foundation; either
  * version 2 of the License, or (at your option) any later version.
  *
  * This library is distributed in the hope that it will be useful,
  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  * Library General Public License for more details.
  *
  * You should have received a copy of the GNU Library General Public License
  * along with this library; see the file COPYING.LIB.  If not, write to
  * the Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor,
  * Boston, MA 02110-1301, USA.
  */
 
 #include "core/page/FrameTree.h"
 
 #include "core/dom/Document.h"
 #include "core/frame/FrameClient.h"
 #include "core/frame/FrameView.h"
 #include "core/frame/LocalFrame.h"
 #include "core/frame/RemoteFrame.h"
 #include "core/frame/RemoteFrameView.h"
+#include "core/frame/UseCounter.h"
 #include "core/page/Page.h"
 #include "wtf/Assertions.h"
 #include "wtf/Vector.h"
 #include "wtf/text/CString.h"
 #include "wtf/text/StringBuilder.h"
 
 using std::swap;
 
 namespace blink {
 
 namespace {
 
 const unsigned invalidChildCount = ~0U;
 
 }  // namespace
 
 FrameTree::FrameTree(Frame* thisFrame)
     : m_thisFrame(thisFrame), m_scopedChildCount(invalidChildCount) {}
 
 FrameTree::~FrameTree() {}
 
+const AtomicString& FrameTree::name() const {
+  // TODO(andypaicu): remove this once we have gathered the data
+  if (m_experimentalSetNulledName) {
+    UseCounter::count(m_thisFrame.get(),
+                      UseCounter::CrossOriginMainFrameNulledNameAccessed);
+  }
+  return m_name;
+}
+
+// TODO(andypaicu): remove this once we have gathered the data
+void FrameTree::experimentalSetNulledName() {
+  m_experimentalSetNulledName = true;
+}
+
 void FrameTree::setName(const AtomicString& name) {
+  // TODO(andypaicu): remove this once we have gathered the data
+  m_experimentalSetNulledName = false;
   m_name = name;
 }
 
 DISABLE_CFI_PERF
 Frame* FrameTree::parent() const {
   if (!m_thisFrame->client())
     return nullptr;
   return m_thisFrame->client()->parent();
 }
 
@@ skipping 217 matching lines @@
 void showFrameTree(const blink::Frame* frame) {
   if (!frame) {
     printf("Null input frame\n");
     return;
   }
 
   printFrames(frame->tree().top(), frame, 0);
 }
 
 #endif