Makes RenderFrameObserver/RenderViewObserver::OnDestruct pure virtual.

content/renderer/devtools/devtools_agent.cc

 // Copyright (c) 2012 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/devtools/devtools_agent.h"
 
 #include <stddef.h>
 
 #include <map>
 
@@ skipping 89 matching lines @@
   if (message.type() == FrameMsg_Navigate::ID)
     ContinueProgram();  // Don't want to swallow the message.
 
   return handled;
 }
 
 void DevToolsAgent::WidgetWillClose() {
   ContinueProgram();
 }
 
+void DevToolsAgent::OnDestruct() {
+  delete this;
+}
+
 void DevToolsAgent::sendProtocolMessage(int session_id,
                                         int call_id,
                                         const blink::WebString& message,
                                         const blink::WebString& state_cookie) {
   if (!send_protocol_message_callback_for_test_.is_null()) {
     send_protocol_message_callback_for_test_.Run(
         session_id, call_id, message.utf8(), state_cookie.utf8());
     return;
   }
   SendChunkedProtocolMessage(this, routing_id(), session_id, call_id,
@@ skipping 193 matching lines @@
   result->Set("errors", errors.release());
   response->Set("result", result.release());
 
   std::string json_message;
   base::JSONWriter::Write(*response, &json_message);
   SendChunkedProtocolMessage(this, routing_id(), session_id, call_id,
                              json_message, std::string());
 }
 
 }  // namespace content