Move FrameHost::m_subframeCount to Page

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

Index: third_party/WebKit/Source/core/page/Page.cpp
diff --git a/third_party/WebKit/Source/core/page/Page.cpp b/third_party/WebKit/Source/core/page/Page.cpp
index 65140b70f936b57305e88f7500b8f5d792536792..dc655f9a5d8db3fc70e19884559c2b71527583ef 100644
--- a/third_party/WebKit/Source/core/page/Page.cpp
+++ b/third_party/WebKit/Source/core/page/Page.cpp
@@ -118,6 +118,7 @@ Page::Page(PageClients& pageClients)
       m_deviceScaleFactor(1),
       m_visibilityState(PageVisibilityStateVisible),
       m_isCursorVisible(true),
+      m_subframeCount(0),
       m_frameHost(FrameHost::create(*this)) {
   ASSERT(m_editorClient);
 
@@ -378,6 +379,25 @@ bool Page::isCursorVisible() const {
   return m_isCursorVisible;
 }
 
+#if DCHECK_IS_ON()
+void checkFrameCountConsistency(int expectedFrameCount, Frame* frame) {
+  DCHECK_GE(expectedFrameCount, 0);
+
+  int actualFrameCount = 0;
+  for (; frame; frame = frame->tree().traverseNext())
+    ++actualFrameCount;
+
+  DCHECK_EQ(expectedFrameCount, actualFrameCount);
+}
+#endif
+
+int Page::subframeCount() const {
+#if DCHECK_IS_ON()
+  checkFrameCountConsistency(m_subframeCount + 1, mainFrame());
+#endif
+  return m_subframeCount;
+}
+
 void Page::settingsChanged(SettingsDelegate::ChangeType changeType) {
   switch (changeType) {
     case SettingsDelegate::StyleChange: