Makes RenderFrameObserver/RenderViewObserver::OnDestruct pure virtual.

content/public/renderer/render_view_observer.cc

 // Copyright (c) 2011 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/public/renderer/render_view_observer.h"
 
 #include "content/renderer/render_view_impl.h"
 
 namespace content {
 
 RenderViewObserver::RenderViewObserver(RenderView* render_view)
     : render_view_(static_cast<RenderViewImpl*>(render_view)),
       routing_id_(MSG_ROUTING_NONE) {
   // |render_view_| can be null on unit testing or if Observe() is used.
   if (render_view_) {
     routing_id_ = render_view_->GetRoutingID();
     // TODO(jam): bring this back DCHECK_NE(routing_id_, MSG_ROUTING_NONE);
     render_view_->AddObserver(this);
   }
 }
 
 RenderViewObserver::~RenderViewObserver() {
   if (render_view_)
     render_view_->RemoveObserver(this);
 }
 
-void RenderViewObserver::OnDestruct() {
-  delete this;
-}
-
 bool RenderViewObserver::OnMessageReceived(const IPC::Message& message) {
   return false;
 }
 
 bool RenderViewObserver::Send(IPC::Message* message) {
   if (render_view_)
     return render_view_->Send(message);
 
   delete message;
   return false;
@@ skipping 14 matching lines @@
   }
 
   render_view_ = static_cast<RenderViewImpl*>(render_view);
   if (render_view_) {
     routing_id_ = render_view_->GetRoutingID();
     render_view_->AddObserver(this);
   }
 }
 
 }  // namespace content