Refactor code that defers extension background page loading

extensions/browser/process_manager.h

Index: extensions/browser/process_manager.h
diff --git a/extensions/browser/process_manager.h b/extensions/browser/process_manager.h
index 664c9420fde504a05d071e6de9a9a232722b57fa..6acc267ca68e2a0711b846db04eb761de754215e 100644
--- a/extensions/browser/process_manager.h
+++ b/extensions/browser/process_manager.h
@@ -125,6 +125,14 @@ class ProcessManager : public content::NotificationObserver {
   // Ensures background hosts are loaded for a new browser window.
   void OnBrowserWindowReady();
 
+  // Notifies the ProcessManager that a BrowserContext is fully initialized.
+  // A BrowserContext might be initialized asynchronously (in parallel with
+  // extension system startup). The ProcessManager needs to know when that
+  // initialization is complete so it can load deferred background pages.
+  // (See NOTIFICATION_PROFILE_CREATED in Chrome and IsContextValid() in
+  // ExtensionsBrowserClient).
+  void OnBrowserContextValid(content::BrowserContext* context);
+
   // Gets the BrowserContext associated with site_instance_ and all other
   // related SiteInstances.
   content::BrowserContext* GetBrowserContext() const;
@@ -144,6 +152,10 @@ class ProcessManager : public content::NotificationObserver {
       content::BrowserContext* original_context,
       ProcessManager* original_manager);
 
+  bool startup_background_hosts_created_for_test() const {
+    return startup_background_hosts_created_;
+  }
+
  protected:
   // If |context| is incognito pass the master context as |original_context|.
   // Otherwise pass the same context for both.
@@ -158,9 +170,8 @@ class ProcessManager : public content::NotificationObserver {
                        const content::NotificationSource& source,
                        const content::NotificationDetails& details) OVERRIDE;
 
-  // Load all background pages once the profile data is ready and the pages
-  // should be loaded.
-  void CreateBackgroundHostsForProfileStartup();
+  // Loads all background pages for a BrowserContext if everything is ready.
+  void MaybeCreateBackgroundHostsForStartup();
 
   content::NotificationRegistrar registrar_;