Change ScriptContextTest.GetEffectiveDocumentURL to use FrameLoadWaiter and re-enable the test.

content/test/frame_load_waiter.cc

-// Copyright 2014 The Chromium Authors. All rights reserved.
-// Use of this source code is governed by a BSD-style license that can be
-// found in the LICENSE file.
-
-#include "content/test/frame_load_waiter.h"
-
-#include "base/location.h"
-#include "base/message_loop/message_loop.h"
-
-namespace content {
-
-FrameLoadWaiter::FrameLoadWaiter(RenderFrame* frame)
-    : RenderFrameObserver(frame) {
-}
-
-void FrameLoadWaiter::Wait() {
-  // Pump messages until Blink's threaded HTML parser finishes.
-  run_loop_.Run();
-}
-
-void FrameLoadWaiter::DidFinishLoad() {
-  // Post a task to quit instead of quitting directly, since the load completion
-  // may trigger other IPCs that tests are expecting.
-  base::MessageLoop::current()->PostTask(FROM_HERE, run_loop_.QuitClosure());
-}
-
-}  // namespace content