Add Frame::isMainFrame and deploy it

Source/core/frame/DOMWindow.cpp

 /*
  * Copyright (C) 2006, 2007, 2008, 2010 Apple Inc. All rights reserved.
  * Copyright (C) 2010 Nokia Corporation and/or its subsidiary(-ies)
  *
  * 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
@@ skipping 220 matching lines @@
     if (set.isEmpty())
         enableSuddenTermination();
 }
 
 static bool allowsBeforeUnloadListeners(DOMWindow* window)
 {
     ASSERT_ARG(window, window);
     Frame* frame = window->frame();
     if (!frame)
         return false;
-    Page* page = frame->page();
-    if (!page)
-        return false;
-    return frame == page->mainFrame();
+    return frame->isMainFrame();
 }
 
 unsigned DOMWindow::pendingUnloadEventListeners() const
 {
     return windowsWithUnloadEventListeners().count(const_cast<DOMWindow*>(this));
 }
 
 // This function:
 // 1) Validates the pending changes are not changing any value to NaN; in that case keep original value.
 // 2) Constrains the window rect to the minimum window size and no bigger than the float rect's dimensions.
@@ skipping 141 matching lines @@
     if (m_frame->page() && m_frame->view()) {
         if (ScrollingCoordinator* scrollingCoordinator = m_frame->page()->scrollingCoordinator()) {
             scrollingCoordinator->scrollableAreaScrollbarLayerDidChange(m_frame->view(), HorizontalScrollbar);
             scrollingCoordinator->scrollableAreaScrollbarLayerDidChange(m_frame->view(), VerticalScrollbar);
             scrollingCoordinator->scrollableAreaScrollLayerDidChange(m_frame->view());
         }
     }
 
     m_frame->selection().updateSecureKeyboardEntryIfActive();
 
-    if (m_frame->page() && m_frame->page()->mainFrame() == m_frame) {
+    if (m_frame->isMainFrame()) {
         m_frame->page()->mainFrame()->notifyChromeClientWheelEventHandlerCountChanged();
         if (m_document->hasTouchEventHandlers())
             m_frame->page()->chrome().client().needTouchEvents(true);
     }
 
     return m_document;
 }
 
 EventQueue* DOMWindow::eventQueue() const
 {
@@ skipping 519 matching lines @@
 
     bool allowFocus = WindowFocusAllowedIndicator::windowFocusAllowed();
     if (context) {
         ASSERT(isMainThread());
         Document* activeDocument = toDocument(context);
         if (opener() && opener() != this && activeDocument->domWindow() == opener())
             allowFocus = true;
     }
 
     // If we're a top level window, bring the window to the front.
-    if (m_frame == page->mainFrame() && allowFocus)
+    if (m_frame->isMainFrame() && allowFocus)
         page->chrome().focus();
 
     if (!m_frame)
         return;
 
     m_frame->eventHandler().focusDocumentView();
 }
 
 void DOMWindow::blur()
 {
@@ skipping 910 matching lines @@
     return static_cast<DOMWindowLifecycleNotifier&>(LifecycleContext::lifecycleNotifier());
 }
 
 PassOwnPtr<LifecycleNotifier<DOMWindow> > DOMWindow::createLifecycleNotifier()
 {
     return DOMWindowLifecycleNotifier::create(this);
 }
 
 
 } // namespace WebCore