Use process-per-app-instance for hosted apps without background permission.

chrome/browser/extensions/extension_process_manager.h

 // 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.
 
 #ifndef CHROME_BROWSER_EXTENSIONS_EXTENSION_PROCESS_MANAGER_H_
 #define CHROME_BROWSER_EXTENSIONS_EXTENSION_PROCESS_MANAGER_H_
 #pragma once
 
 #include <map>
 #include <set>
@@ skipping 50 matching lines @@
   virtual void CreateBackgroundHost(const Extension* extension,
                                     const GURL& url);
 
   // Gets the ExtensionHost for the background page for an extension, or NULL if
   // the extension isn't running or doesn't have a background page.
   ExtensionHost* GetBackgroundHostForExtension(const Extension* extension);
 
   // Returns the SiteInstance that the given URL belongs to.
   virtual SiteInstance* GetSiteInstanceForURL(const GURL& url);
 
-  // Registers an extension process by |extension_id| and specifying which
-  // |process_id| it belongs to.
-  void RegisterExtensionProcess(const std::string& extension_id,
-                                int process_id);
-
-  // Unregisters an extension process with specified |process_id|.
-  void UnregisterExtensionProcess(int process_id);
-
   // Returns the extension process that |url| is associated with if it exists.
   virtual RenderProcessHost* GetExtensionProcess(const GURL& url);
 
   // Returns the process that the extension with the given ID is running in.
   RenderProcessHost* GetExtensionProcess(const std::string& extension_id);
 
   // Returns true if |host| is managed by this process manager.
   bool HasExtensionHost(ExtensionHost* host) const;
 
   typedef std::set<ExtensionHost*> ExtensionHostSet;
@@ skipping 20 matching lines @@
   // The set of all ExtensionHosts managed by this process manager.
   ExtensionHostSet all_hosts_;
 
   // The set of running viewless background extensions.
   ExtensionHostSet background_hosts_;
 
   // The BrowsingInstance shared by all extensions in this profile.  This
   // controls process grouping.
   scoped_refptr<BrowsingInstance> browsing_instance_;
 
-  // A map of extension ID to the render_process_id that the extension lives in.
-  typedef std::map<std::string, int> ProcessIDMap;
-  ProcessIDMap process_ids_;
-
   DISALLOW_COPY_AND_ASSIGN(ExtensionProcessManager);
 };
 
 #endif  // CHROME_BROWSER_EXTENSIONS_EXTENSION_PROCESS_MANAGER_H_