Simplify handling of LocalFrame lifecycle notifications.

Source/core/frame/LocalFrameLifecycleNotifier.h

Index: Source/core/frame/LocalFrameLifecycleNotifier.h
diff --git a/Source/core/frame/LocalFrameLifecycleNotifier.h b/Source/core/frame/LocalFrameLifecycleNotifier.h
new file mode 100644
index 0000000000000000000000000000000000000000..cd3c85b1d515b66e484fcd04daee66c03c8e5baa
--- /dev/null
+++ b/Source/core/frame/LocalFrameLifecycleNotifier.h
@@ -0,0 +1,24 @@
+// Copyright 2015 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 LocalFrameLifecycleNotifier_h
+#define LocalFrameLifecycleNotifier_h
+
+#include "core/CoreExport.h"
+#include "platform/LifecycleNotifier.h"
+#include "wtf/Forward.h"
+
+namespace blink {
+
+class FrameDestructionObserver;
+class LocalFrame;
+
+class CORE_EXPORT LocalFrameLifecycleNotifier : public LifecycleNotifier<LocalFrame, FrameDestructionObserver> {
+public:
+    void notifyWillDetachFrameHost();
+};
+
+} // namespace blink
+
+#endif // LocalFrameLifecycleNotifier_h