Initialize the new WindowProxy when handing off the global object.

Source/bindings/core/v8/WindowProxy.cpp

Index: Source/bindings/core/v8/WindowProxy.cpp
diff --git a/Source/bindings/core/v8/WindowProxy.cpp b/Source/bindings/core/v8/WindowProxy.cpp
index c88a6e57b0d6dcfacd6c45ddb8933eebbe9db69f..d5a04620c83830d8ca6ebcc6ce3a58ce3a156455 100644
--- a/Source/bindings/core/v8/WindowProxy.cpp
+++ b/Source/bindings/core/v8/WindowProxy.cpp
@@ -156,6 +156,13 @@ void WindowProxy::takeGlobalFrom(WindowProxy* windowProxy)
         ASSERT(windowProxy->m_scriptState->isGlobalObjectDetached());
     m_global.set(m_isolate, windowProxy->m_global.newLocal(m_isolate));
     windowProxy->m_global.clear();
+    // Initialize the window proxy now, to re-establish the connection between
+    // the global object and the v8::Context. This is really only needed for a
+    // RemoteDOMWindow, since it has no scripting environment of its own.
+    // Without this, existing script references to a swapped in RemoteDOMWindow
+    // would be broken until that RemoteDOMWindow was vended again through an
+    // interface like window.frames.
+    initializeIfNeeded();

[haraken, 2015/04/24 05:06:04]

Just to confirm: This initializeIfNeeded() creates a new Context and its global
object but doesn't set the newly created global object to m_global (because
you've already set m_global in the above). Is this expected?

 }
 
 // Create a new environment and setup the global object.
@@ -397,8 +404,8 @@ void WindowProxy::setSecurityToken(SecurityOrigin* origin)
     // - the frame is showing the initial empty document
     // - the frame is remote
     bool delaySet = m_world->isMainWorld()
-        && (origin->domainWasSetInDOM()
-            || m_frame->isRemoteFrame()
+        && (m_frame->isRemoteFrame()
+            || origin->domainWasSetInDOM()
             || toLocalFrame(m_frame)->loader().stateMachine()->isDisplayingInitialEmptyDocument());
     if (origin && !delaySet)
         token = origin->toString();