Allow going fullscreen during a screen orientation change handler.

third_party/WebKit/Source/platform/ScopedOrientationChangeIndicator.cpp

+// Copyright 2016 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 "platform/ScopedOrientationChangeIndicator.h"
+
+#include "wtf/Assertions.h"
+
+namespace blink {
+
+ScopedOrientationChangeIndicator::State ScopedOrientationChangeIndicator::s_state = ScopedOrientationChangeIndicator::State::NotProcessing;
+
+ScopedOrientationChangeIndicator::ScopedOrientationChangeIndicator()
+{
+    DCHECK(isMainThread());
+
+    m_previousState = s_state;
+    s_state = State::Processing;
+}
+
+ScopedOrientationChangeIndicator::~ScopedOrientationChangeIndicator()
+{
+    DCHECK(isMainThread());
+    s_state = m_previousState;
+}
+
+// static
+bool ScopedOrientationChangeIndicator::processingOrientationChange()
+{
+    DCHECK(isMainThread());
+    return s_state == State::Processing;
+}
+
+} // namespace blink