Revert of Remove WindowFocusAllowedIndicator and associated code.

Source/core/page/WindowFocusAllowedIndicator.cpp

+/*
+ * Copyright (C) 2012 Google, Inc. All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ * 1. Redistributions of source code must retain the above copyright
+ *    notice, this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright
+ *    notice, this list of conditions and the following disclaimer in the
+ *    documentation and/or other materials provided with the distribution.
+ *
+ * THIS SOFTWARE IS PROVIDED BY GOOGLE INC. ``AS IS'' AND ANY
+ * EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+ * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
+ * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL APPLE COMPUTER, INC. OR
+ * CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
+ * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
+ * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
+ * PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY
+ * OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+ * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+ * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ */
+
+#include "config.h"
+#include "core/page/WindowFocusAllowedIndicator.h"
+
+namespace blink {
+
+static bool s_windowFocusAllowed = false;
+
+bool WindowFocusAllowedIndicator::windowFocusAllowed()
+{
+    return s_windowFocusAllowed;
+}
+
+WindowFocusAllowedIndicator::WindowFocusAllowedIndicator()
+    : m_previousWindowFocusAllowed(s_windowFocusAllowed)
+{
+    s_windowFocusAllowed = true;
+}
+
+WindowFocusAllowedIndicator::~WindowFocusAllowedIndicator()
+{
+    s_windowFocusAllowed = m_previousWindowFocusAllowed;
+}
+
+} // namespace blink