Makes RenderFrameObserver/RenderViewObserver::OnDestruct pure virtual.

content/renderer/screen_orientation/screen_orientation_dispatcher.cc

 // 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 "content/renderer/screen_orientation/screen_orientation_dispatcher.h"
 
 #include "content/common/screen_orientation_messages.h"
 
 namespace content {
 
@@ skipping 13 matching lines @@
     IPC_MESSAGE_HANDLER(ScreenOrientationMsg_LockSuccess,
                         OnLockSuccess)
     IPC_MESSAGE_HANDLER(ScreenOrientationMsg_LockError,
                         OnLockError)
     IPC_MESSAGE_UNHANDLED(handled = false)
   IPC_END_MESSAGE_MAP()
 
   return handled;
 }
 
+void ScreenOrientationDispatcher::OnDestruct() {
+  delete this;
+}
+
 void ScreenOrientationDispatcher::OnLockSuccess(int request_id) {
   blink::WebLockOrientationCallback* callback =
       pending_callbacks_.Lookup(request_id);
   if (!callback)
     return;
   callback->onSuccess();
   pending_callbacks_.Remove(request_id);
 }
 
 void ScreenOrientationDispatcher::OnLockError(
@@ skipping 23 matching lines @@
   Send(new ScreenOrientationHostMsg_LockRequest(
       routing_id(), orientation, request_id));
 }
 
 void ScreenOrientationDispatcher::unlockOrientation() {
   CancelPendingLocks();
   Send(new ScreenOrientationHostMsg_Unlock(routing_id()));
 }
 
 }  // namespace content