Remove PushPermissionClient.

Source/modules/push_messaging/PushPermissionClient.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 PushPermissionClient_h
-#define PushPermissionClient_h
-
-#include "platform/Supplementable.h"
-#include "public/platform/WebCallback.h"
-#include "wtf/PassOwnPtr.h"
-
-namespace blink {
-
-class ExecutionContext;
-class LocalFrame;
-
-class PushPermissionClient : public WillBeHeapSupplement<LocalFrame> {
-public:
-    virtual ~PushPermissionClient() { }
-
-    // Requests user permission to use the Push API from the origin of the
-    // current frame. The provided callback will be run when a decision has been
-    // made.
-    virtual void requestPermission(ExecutionContext*, WebCallback*) = 0;
-
-    // WillBeHeapSupplement requirements.
-    static const char* supplementName();
-    static PushPermissionClient* from(ExecutionContext*);
-};
-
-void providePushPermissionClientTo(LocalFrame&, PassOwnPtrWillBeRawPtr<PushPermissionClient>);
-
-} // namespace blink
-
-#endif // PushPermissionClient_h