Remove an isContextInitialized() check from ScriptController::windowProxy()

WindowProxy::initializeIfNeeded() is no-op when isContextInitialized() returns true.
So we can remove the check from ScriptController::windowProxy() and unconditionally
call WindowProxy::initializeIfNeeded().

This CL will cause a subtle change: Before this CL, dispatchDidClearWindowObjectInMainWorld
was not called if WindowProxy gets initialized via WindowProxy::setGlobal. After this CL,
dispatchDidClearWindowObjectInMainWorld will be called always when WindowProxy gets initialized.
I don't think the difference matters (and I guess the new behavior will be more correct).

BUG=677253

Review-Url: https://codereview.chromium.org/2613893002
Cr-Commit-Position: refs/heads/master@{#441908}

third_party/WebKit/Source/bindings/core/v8/ScriptController.cpp

@@ -211,11 +211,7 @@ void ScriptController::executeScriptInMainWorld(
 
 WindowProxy* ScriptController::windowProxy(DOMWrapperWorld& world) {
   WindowProxy* windowProxy = m_windowProxyManager->windowProxy(world);
-  if (!windowProxy->isContextInitialized()) {
-    windowProxy->initializeIfNeeded();
-    if (world.isMainWorld())
-      frame()->loader().dispatchDidClearWindowObjectInMainWorld();
-  }
+  windowProxy->initializeIfNeeded();
   return windowProxy;
 }
 

third_party/WebKit/Source/bindings/core/v8/WindowProxy.cpp

@@ -214,6 +214,9 @@ void WindowProxy::initializeIfNeeded() {
   if (isContextInitialized())
     return;
   initialize();
+
+  if (m_world->isMainWorld() && m_frame->isLocalFrame())
+    toLocalFrame(m_frame)->loader().dispatchDidClearWindowObjectInMainWorld();
 }
 
 void WindowProxy::initialize() {