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

chrome/browser/extensions/extension_process_manager.h

Index: chrome/browser/extensions/extension_process_manager.h
diff --git a/chrome/browser/extensions/extension_process_manager.h b/chrome/browser/extensions/extension_process_manager.h
index 8bf5e7781350e6f5ca30d13795a5f648cea62257..9f1f9bc048c41e5b0531a4b11bb98c21aaf409c9 100644
--- a/chrome/browser/extensions/extension_process_manager.h
+++ b/chrome/browser/extensions/extension_process_manager.h
@@ -68,14 +68,6 @@ class ExtensionProcessManager : public NotificationObserver {
   // 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);
 
@@ -116,10 +108,6 @@ class ExtensionProcessManager : public NotificationObserver {
   // 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);
 };