athena: Remove ActivityViewModel::CreateWidget().

athena/content/app_activity_proxy.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 "athena/content/app_activity_proxy.h"
 
 #include "athena/content/app_activity.h"
 #include "athena/content/app_activity_registry.h"
 #include "athena/wm/public/window_list_provider.h"
 #include "athena/wm/public/window_manager.h"
@@ skipping 34 matching lines @@
 bool AppActivityProxy::IsVisible() {
   return false;
 }
 
 Activity::ActivityMediaState AppActivityProxy::GetMediaState() {
   // This proxy has never any media playing.
   return ACTIVITY_MEDIA_STATE_NONE;
 }
 
 aura::Window* AppActivityProxy::GetWindow() {
-  return view_->GetWidget()->GetNativeWindow();
+  return view_->GetWidget() ? view_->GetWidget()->GetNativeWindow() : nullptr;
 }
 
 content::WebContents* AppActivityProxy::GetWebContents() {
   return nullptr;
 }
 
 void AppActivityProxy::Init() {
   DCHECK(replaced_activity_);
   // Get the content proxy to present the content.
   content_proxy_ = replaced_activity_->GetContentProxy();
@@ skipping 19 matching lines @@
 }
 
 bool AppActivityProxy::UsesFrame() const {
   return true;
 }
 
 views::View* AppActivityProxy::GetContentsView() {
   return view_;
 }
 
-views::Widget* AppActivityProxy::CreateWidget() {
-  return nullptr;
-}
-
 gfx::ImageSkia AppActivityProxy::GetOverviewModeImage() {
   return content_proxy_->GetContentImage();
 }
 
 void AppActivityProxy::PrepareContentsForOverview() {
 }
 
 void AppActivityProxy::ResetContentsView() {
 }
 
 AppActivityProxy::~AppActivityProxy() {
   app_activity_registry_->ProxyDestroyed(this);
 }
 
 }  // namespace athena