MainFrameObserver is inline owned, so it shouldn't be freed by OnDestruct

content/renderer/web_ui_mojo.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/web_ui_mojo.h"
 
 #include "content/common/view_messages.h"
 #include "content/public/renderer/render_frame.h"
 #include "content/public/renderer/render_view.h"
 #include "content/renderer/web_ui_mojo_context_state.h"
@@ skipping 27 matching lines @@
 void WebUIMojo::MainFrameObserver::WillReleaseScriptContext(
     v8::Local<v8::Context> context,
     int world_id) {
   web_ui_mojo_->DestroyContextState(context);
 }
 
 void WebUIMojo::MainFrameObserver::DidFinishDocumentLoad() {
   web_ui_mojo_->OnDidFinishDocumentLoad();
 }
 
+void WebUIMojo::MainFrameObserver::OnDestruct() {
+}
+
 WebUIMojo::WebUIMojo(RenderView* render_view)
     : RenderViewObserver(render_view),
       RenderViewObserverTracker<WebUIMojo>(render_view),
       main_frame_observer_(this) {
 }
 
 WebUIMojo::~WebUIMojo() {
 }
 
 void WebUIMojo::CreateContextState() {
@@ skipping 53 matching lines @@
   // be empty and we don't need to destroy it.
   WebUIMojoContextState* state = GetContextState();
   if (state && !state->module_added())
     return;
 
   v8::HandleScope handle_scope(blink::mainThreadIsolate());
   DestroyContextState(frame->mainWorldScriptContext());
 }
 
 }  // namespace content