Break extensions ProcessManager dependency on Runtime API

extensions/browser/process_manager.h

 // 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.
 
 #ifndef EXTENSIONS_BROWSER_PROCESS_MANAGER_H_
 #define EXTENSIONS_BROWSER_PROCESS_MANAGER_H_
 
 #include <map>
 #include <set>
 #include <string>
 
 #include "base/callback.h"
 #include "base/compiler_specific.h"
 #include "base/memory/ref_counted.h"
 #include "base/memory/weak_ptr.h"
+#include "base/observer_list.h"
 #include "base/time/time.h"
 #include "content/public/browser/notification_observer.h"
 #include "content/public/browser/notification_registrar.h"
 #include "extensions/common/view_type.h"
 
 class GURL;
 
 namespace content {
 class BrowserContext;
 class DevToolsAgentHost;
 class RenderViewHost;
 class RenderFrameHost;
 class SiteInstance;
 };
 
 namespace extensions {
 
 class Extension;
 class ExtensionHost;
+class ProcessManagerObserver;
 
 // Manages dynamic state of running Chromium extensions. There is one instance
 // of this class per Profile. OTR Profiles have a separate instance that keeps
 // track of split-mode extensions only.
 class ProcessManager : public content::NotificationObserver {
  public:
   typedef std::set<extensions::ExtensionHost*> ExtensionHostSet;
   typedef ExtensionHostSet::const_iterator const_iterator;
 
   static ProcessManager* Create(content::BrowserContext* context);
   virtual ~ProcessManager();
 
   const ExtensionHostSet& background_hosts() const {
     return background_hosts_;
   }
 
   typedef std::set<content::RenderViewHost*> ViewSet;
   const ViewSet GetAllViews() const;
 
+  // The typical observer interface.
+  void AddObserver(ProcessManagerObserver* observer);
+  void RemoveObserver(ProcessManagerObserver* observer);
+
   // Creates a new UI-less extension instance.  Like CreateViewHost, but not
   // displayed anywhere.  Returns false if no background host can be created,
   // for example for hosted apps and extensions that aren't enabled in
   // Incognito.
   virtual bool 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 std::string& extension_id);
@@ skipping 167 matching lines @@
   base::TimeDelta event_page_suspending_time_;
 
   // True if we have created the startup set of background hosts.
   bool startup_background_hosts_created_;
 
   base::Callback<void(content::DevToolsAgentHost*, bool)> devtools_callback_;
 
   ImpulseCallbackForTesting keepalive_impulse_callback_for_testing_;
   ImpulseCallbackForTesting keepalive_impulse_decrement_callback_for_testing_;
 
+  ObserverList<ProcessManagerObserver> observer_list_;
+
   base::WeakPtrFactory<ProcessManager> weak_ptr_factory_;
 
   DISALLOW_COPY_AND_ASSIGN(ProcessManager);
 };
 
 }  // namespace extensions
 
 #endif  // EXTENSIONS_BROWSER_PROCESS_MANAGER_H_