Track where WebContents are created in order to better understand issue.

chrome/browser/extensions/api/tabs/ash_panel_contents.cc

 // Copyright 2013 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 "chrome/browser/extensions/api/tabs/ash_panel_contents.h"
 
 #include "base/values.h"
 #include "chrome/browser/chrome_notification_types.h"
 #include "chrome/browser/extensions/api/tabs/tabs_constants.h"
 #include "chrome/browser/extensions/api/tabs/tabs_windows_api.h"
 #include "chrome/browser/extensions/api/tabs/windows_event_router.h"
 #include "chrome/browser/extensions/extension_tab_util.h"
 #include "chrome/browser/extensions/window_controller_list.h"
 #include "chrome/browser/profiles/profile.h"
 #include "chrome/browser/sessions/session_tab_helper.h"
 #include "content/public/browser/browser_context.h"
 #include "content/public/browser/site_instance.h"
 #include "content/public/browser/web_contents.h"
+#include "content/public/browser/web_contents_source.h"
 #include "extensions/browser/app_window/native_app_window.h"
 #include "extensions/common/extension.h"
 #include "extensions/common/permissions/api_permission.h"
 #include "extensions/common/permissions/permissions_data.h"
 #include "ui/gfx/image/image.h"
 
 using extensions::AppWindow;
 using extensions::NativeAppWindow;
 
 // AshPanelContents -----------------------------------------------------
 
 AshPanelContents::AshPanelContents(AppWindow* host) : host_(host) {}
 
 AshPanelContents::~AshPanelContents() {
 }
 
 void AshPanelContents::Initialize(content::BrowserContext* context,
                                   const GURL& url) {
   url_ = url;
 
   web_contents_.reset(
       content::WebContents::Create(content::WebContents::CreateParams(
           context, content::SiteInstance::CreateForURL(context, url_))));
+  WebContentsSource::CreateForWebContentsAndLocation(web_contents_.get(),
+                                                     FROM_HERE);
 
   // Needed to give the web contents a Window ID. Extension APIs expect web
   // contents to have a Window ID. Also required for FaviconDriver to correctly
   // set the window icon and title.
   SessionTabHelper::CreateForWebContents(web_contents_.get());
   SessionTabHelper::FromWebContents(web_contents_.get())->SetWindowID(
       host_->session_id());
 
   // Responsible for loading favicons for the Launcher, which uses different
   // logic than the FaviconDriver associated with web_contents_ (instantiated in
@@ skipping 25 matching lines @@
 
 extensions::WindowController* AshPanelContents::GetWindowController() const {
   return nullptr;
 }
 
 void AshPanelContents::FaviconUpdated() {
   gfx::Image new_image = gfx::Image::CreateFrom1xBitmap(
       launcher_favicon_loader_->GetFavicon());
   host_->UpdateAppIcon(new_image);
 }