Get rid of extensions dependency from content\browser.

chrome/browser/chrome_content_browser_client.cc

 // Copyright (c) 2011 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/chrome_content_browser_client.h"
 
 #include "chrome/browser/profiles/profile.h"
 #include "chrome/browser/extensions/extension_service.h"
 #include "chrome/browser/renderer_host/browser_render_process_host.h"
 #include "chrome/browser/ui/webui/chrome_web_ui_factory.h"
@@ skipping 14 matching lines @@
     const Extension* installed_app = service->GetInstalledApp(url);
     static_cast<BrowserRenderProcessHost*>(render_view_host->process())->
         set_installed_app(installed_app);
   }
 }
 
 content::WebUIFactory* ChromeContentBrowserClient::GetWebUIFactory() {
   return ChromeWebUIFactory::GetInstance();
 }
 
+GURL ChromeContentBrowserClient::GetEffectiveURL(Profile* profile,
+                                                 const GURL& url) {
+  // Get the effective URL for the given actual URL. If the URL is part of an
+  // installed app, the effective URL is an extension URL with the ID of that
+  // extension as the host. This has the effect of grouping apps together in
+  // a common SiteInstance.
+  if (!profile || !profile->GetExtensionService())
+    return url;
+
+  const Extension* extension =
+      profile->GetExtensionService()->GetExtensionByWebExtent(url);
+  if (!extension)
+    return url;
+
+  // If the URL is part of an extension's web extent, convert it to an
+  // extension URL.
+  return extension->GetResourceURL(url.path());
+}
+
 }  // namespace chrome