Prepare for remote->local frame swap

Source/web/WebLocalFrameImpl.cpp

Index: Source/web/WebLocalFrameImpl.cpp
diff --git a/Source/web/WebLocalFrameImpl.cpp b/Source/web/WebLocalFrameImpl.cpp
index c508c7f825670dc38d164d6192373edcbba25fd8..ade203f748b3ad84d83bbdd4342c1380b02d342b 100644
--- a/Source/web/WebLocalFrameImpl.cpp
+++ b/Source/web/WebLocalFrameImpl.cpp
@@ -205,6 +205,7 @@
 #include "web/WebDataSourceImpl.h"
 #include "web/WebDevToolsAgentPrivate.h"
 #include "web/WebPluginContainerImpl.h"
+#include "web/WebRemoteFrameImpl.h"
 #include "web/WebViewImpl.h"
 #include "wtf/CurrentTime.h"
 #include "wtf/HashMap.h"
@@ -1803,6 +1804,18 @@ void WebLocalFrameImpl::loadJavaScriptURL(const KURL& url)
         frame()->loader().replaceDocumentWhileExecutingJavaScriptURL(scriptResult, ownerDocument.get());
 }
 
+void WebLocalFrameImpl::initializeToReplaceRemoteFrame(WebRemoteFrame* oldWebFrame)
+{
+    Frame* oldFrame = toCoreFrame(oldWebFrame);
+    m_frame = LocalFrame::create(&m_frameLoaderClientImpl, oldFrame->host(), new PlaceholderFrameOwner());

[dcheng, 2014/10/15 21:14:35]

Is PlaceholderFrameOwner the right one? Do we not bother enforcing any sandbox
flags, etc while the load is in progress?

[Nate Chapin, 2014/10/15 21:27:31]

I don't think we enforce them in the provisional state of the first real load,
but I'm not certian. Will look.

[Nate Chapin, 2014/10/16 21:45:56]

This function now creates the LocalFrame with a PlaceholderFrameOwner, then
immediately replaces it with the actual owner. This is because we can't create
the LocalFrame with a null FrameOwner (which would cause this to be the main
frame), nor the real frame owner (which would cause this to become the frame
owner's contentFrame() and perform the swap too soon).

+    m_frame->tree().setName(oldFrame->tree().name());
+    setParent(oldWebFrame->parent());
+    // We must call init() after m_frame is assigned because it is referenced
+    // during init(). Note that this may dispatch JS events; the frame may be
+    // detached after init() returns.
+    m_frame->init();
+}
+
 void WebLocalFrameImpl::sendPings(const WebNode& linkNode, const WebURL& destinationURL)
 {
     ASSERT(frame());