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

content/test/frame_load_waiter.h

-// 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.
-
-#ifndef CONTENT_TEST_FRAME_LOAD_WAITER_H_
-#define CONTENT_TEST_FRAME_LOAD_WAITER_H_
-
-#include "base/macros.h"
-#include "base/run_loop.h"
-#include "content/public/renderer/render_frame_observer.h"
-
-namespace content {
-
-// Helper class to spin the run loop when waiting for a frame load to complete.
-// Blink uses a threaded HTML parser, so it's no longer sufficient to just spin
-// the run loop once to process all pending messages.
-class FrameLoadWaiter : public RenderFrameObserver {
- public:
-  explicit FrameLoadWaiter(RenderFrame* frame);
-  void Wait();
-
- private:
-  virtual void DidFinishLoad() OVERRIDE;
-
-  base::RunLoop run_loop_;
-
-  DISALLOW_COPY_AND_ASSIGN(FrameLoadWaiter);
-};
-
-}  // namespace content
-
-#endif  // CONTENT_TEST_FRAME_LOAD_WAITER_H_