Makes RenderFrameObserver/RenderViewObserver::OnDestruct pure virtual.

content/renderer/devtools/devtools_client.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_client.h"
 
 #include "base/command_line.h"
 #include "base/message_loop/message_loop.h"
 #include "base/strings/utf_string_conversions.h"
 #include "content/common/devtools_messages.h"
@@ skipping 21 matching lines @@
 }
 
 DevToolsClient::~DevToolsClient() {
 }
 
 void DevToolsClient::DidClearWindowObject() {
   if (!compatibility_script_.empty())
     render_frame()->ExecuteJavaScript(base::UTF8ToUTF16(compatibility_script_));
 }
 
+void DevToolsClient::OnDestruct() {
+  delete this;
+}
+
 void DevToolsClient::sendMessageToEmbedder(const WebString& message) {
   Send(new DevToolsHostMsg_DispatchOnEmbedder(routing_id(),
                                               message.utf8()));
 }
 
 bool DevToolsClient::isUnderTest() {
   return RenderThreadImpl::current()->layout_test_mode();
 }
 
 }  // namespace content