Revert 186849 "Bind Window focus ability to the ExecutionContext..."

Source/core/dom/ScopedWindowFocusAllowedIndicator.cpp

Index: Source/core/dom/ScopedWindowFocusAllowedIndicator.cpp
===================================================================
--- Source/core/dom/ScopedWindowFocusAllowedIndicator.cpp	(revision 187183)
+++ Source/core/dom/ScopedWindowFocusAllowedIndicator.cpp	(working copy)
@@ -1,26 +0,0 @@
-// 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 "config.h"
-#include "core/dom/ScopedWindowFocusAllowedIndicator.h"
-
-#include "core/dom/ExecutionContext.h"
-
-namespace blink {
-
-ScopedWindowFocusAllowedIndicator::ScopedWindowFocusAllowedIndicator(
-    ExecutionContext* context)
-    : ContextLifecycleObserver(context)
-{
-    if (executionContext())
-        executionContext()->allowWindowFocus();
-}
-
-ScopedWindowFocusAllowedIndicator::~ScopedWindowFocusAllowedIndicator()
-{
-    if (executionContext())
-        executionContext()->consumeWindowFocus();
-}
-
-} // namespace blink