Add a basic DOMWindow base class and use it in WindowProxy.

Source/core/frame/Frame.h

Index: Source/core/frame/Frame.h
diff --git a/Source/core/frame/Frame.h b/Source/core/frame/Frame.h
index d2a72e85b18cd587c91115936b1c83e5a9b0b5f3..fc2769a1e419f539ddb8b66cd2f3aeb693d4c797 100644
--- a/Source/core/frame/Frame.h
+++ b/Source/core/frame/Frame.h
@@ -59,6 +59,9 @@ public:
     virtual bool isLocalFrame() const { return false; }
     virtual bool isRemoteFrame() const { return false; }
 
+    // FIXME: This should return a DOMWindow*.
+    virtual LocalDOMWindow* domWindow() const = 0;

[dcheng, 2014/10/21 23:22:55]

I meant to include this as a comment, but I'm not sure if making this virtual
will have a perf impact (it was non-virtual before, and inlined too, it looks
like)

[Yuki, 2014/10/23 06:03:34]

IIUC, no one in this CL expects domWindow() returns LocalDOMWindow.  Who expects
LocalDOMWindow?  (I'm just curious.)

[dcheng, 2014/10/23 06:48:46]

A lot of places depend on this to return LocalDOMWindow.
LocalDOMWindow::parent(), top(), opener(), parts of WindowProxy, but also places
in Source/core that do something like
frame->domWindow()->someLocalDOMWindowMethod(). I'm actually working on changing
this in some followup CLs.

+
     virtual void navigate(Document& originDocument, const KURL&, bool lockBackForwardList) = 0;
 
     virtual void detach();
@@ -80,11 +83,6 @@ public:
     void setOwner(FrameOwner* owner) { m_owner = owner; }
     HTMLFrameOwnerElement* deprecatedLocalOwner() const;
 
-    // FIXME: LocalDOMWindow and Document should both be moved to LocalFrame
-    // after RemoteFrame is complete enough to exist without them.
-    virtual void setDOMWindow(PassRefPtrWillBeRawPtr<LocalDOMWindow>);
-    LocalDOMWindow* domWindow() const;
-
     FrameTree& tree() const;
     ChromeClient& chromeClient() const;
 
@@ -110,8 +108,6 @@ protected:
     RawPtrWillBeMember<FrameHost> m_host;
     RawPtrWillBeMember<FrameOwner> m_owner;
 
-    RefPtrWillBeMember<LocalDOMWindow> m_domWindow;
-
 private:
     FrameClient* m_client;
     WebLayer* m_remotePlatformLayer;
@@ -122,11 +118,6 @@ inline FrameClient* Frame::client() const
     return m_client;
 }
 
-inline LocalDOMWindow* Frame::domWindow() const
-{
-    return m_domWindow.get();
-}
-
 inline FrameOwner* Frame::owner() const
 {
     return m_owner;