Remove unused WebFrame::swap() path for local frames.

Source/web/WebLocalFrameImpl.cpp

 /*
  * Copyright (C) 2009 Google Inc. All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions are
  * met:
  *
  *     * Redistributions of source code must retain the above copyright
  * notice, this list of conditions and the following disclaimer.
  *     * Redistributions in binary form must reproduce the above
@@ skipping 1839 matching lines @@
     if (result.IsEmpty() || !result->IsString())
         return;
     String scriptResult = toCoreString(v8::Handle<v8::String>::Cast(result));
     if (!frame()->navigationScheduler().locationChangePending())
         frame()->loader().replaceDocumentWhileExecutingJavaScriptURL(scriptResult, ownerDocument.get());
 }
 
 void WebLocalFrameImpl::initializeToReplaceRemoteFrame(WebRemoteFrame* oldWebFrame)
 {
     Frame* oldFrame = toCoreFrame(oldWebFrame);
-    OwnPtrWillBePersistent<FrameOwner> tempOwner = RemoteBridgeFrameOwner::create(nullptr, SandboxNone);

[dcheng, 2015/02/23 21:05:12]

Btw, is there ever a reason we'd want a stack Persistent? This seems like
something that the Oilpan plugin should warn about.

[haraken, 2015/02/24 00:09:07]

OwnPtrWillBeRawPtr is a right pointer here.

In unit tests, we sometimes need to use persistent handles for on-stack pointers
to protect the pointers from getting collected by
Heap::collectGarbage(NoHeapPointersOnStack) (we use NoHeapPointersOnStack to
make the behavior deterministic (i.e., not conservative)). However, this happens
only in unit tests (*Test.cpp), so I agree that we should improve the plugin to
detect this kind of error.

+    // Note: this *always* temporarily sets a frame owner, even for main frames!
+    // When a core Frame is created with no owner, it attempts to set itself as
+    // the main frame of the Page. However, this is a provisional frame, and may
+    // disappear, so Page::m_mainFrame can't be updated just yet.
+    OwnPtrWillBeRawPtr<FrameOwner> tempOwner = RemoteBridgeFrameOwner::create(nullptr, SandboxNone);
     m_frame = LocalFrame::create(&m_frameLoaderClientImpl, oldFrame->host(), tempOwner.get());
     m_frame->setOwner(oldFrame->owner());
     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();
     m_frame->loader().stateMachine()->advanceTo(m_frameLoaderClientImpl.backForwardLength() > 1 ? FrameLoaderStateMachine::CommittedMultipleRealLoads : FrameLoaderStateMachine::CommittedFirstRealLoad);
 }
@@ skipping 132 matching lines @@
 {
     m_frameWidget = frameWidget;
 }
 
 WebFrameWidgetImpl* WebLocalFrameImpl::frameWidget() const
 {
     return m_frameWidget;
 }
 
 } // namespace blink