Add the ability to load multiple apps into app_shell.

extensions/shell/browser/shell_extension_system.h

 // Copyright 2014 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_SHELL_BROWSER_SHELL_EXTENSION_SYSTEM_H_
 #define EXTENSIONS_SHELL_BROWSER_SHELL_EXTENSION_SYSTEM_H_
 
 #include <vector>
 
 #include "base/compiler_specific.h"
@@ skipping 20 matching lines @@
 class RendererStartupHelper;
 class SharedUserScriptMaster;
 
 // A simplified version of ExtensionSystem for app_shell. Allows
 // app_shell to skip initialization of services it doesn't need.
 class ShellExtensionSystem : public ExtensionSystem {
  public:
   explicit ShellExtensionSystem(content::BrowserContext* browser_context);
   ~ShellExtensionSystem() override;
 
-  // Loads an unpacked application from a directory. Returns true on success.
-  bool LoadApp(const base::FilePath& app_dir);
+  // Loads an unpacked application from a directory. Returns the extension on
+  // success, or null otherwise.
+  const Extension* LoadApp(const base::FilePath& app_dir);
 
-  // Launch the currently loaded app.
-  void LaunchApp();
+  // Initializes the extension system.
+  void Init();
+
+  // Launch the app with id |extension_id|.
+  void LaunchApp(const std::string& extension_id);
 
   // KeyedService implementation:
   void Shutdown() override;
 
-  scoped_refptr<Extension> extension() { return extension_; }
-
   // ExtensionSystem implementation:
   void InitForRegularProfile(bool extensions_enabled) override;
   ExtensionService* extension_service() override;
   RuntimeData* runtime_data() override;
   ManagementPolicy* management_policy() override;
   SharedUserScriptMaster* shared_user_script_master() override;
   ProcessManager* process_manager() override;
   StateStore* state_store() override;
   StateStore* rules_store() override;
   InfoMap* info_map() override;
@@ skipping 12 matching lines @@
   const OneShotEvent& ready() const override;
   ContentVerifier* content_verifier() override;
   scoped_ptr<ExtensionSet> GetDependentExtensions(
       const Extension* extension) override;
   DeclarativeUserScriptMaster* GetDeclarativeUserScriptMasterByExtension(
       const ExtensionId& extension_id) override;
 
  private:
   content::BrowserContext* browser_context_;  // Not owned.
 
-  // Extension ID for the app.
-  std::string app_id_;
-
-  scoped_refptr<Extension> extension_;
-
   // Data to be accessed on the IO thread. Must outlive process_manager_.
   scoped_refptr<InfoMap> info_map_;
 
   scoped_ptr<RuntimeData> runtime_data_;
   scoped_ptr<LazyBackgroundTaskQueue> lazy_background_task_queue_;
   scoped_ptr<EventRouter> event_router_;
   scoped_ptr<ProcessManager> process_manager_;
   scoped_ptr<QuotaService> quota_service_;
 
   // Signaled when the extension system has completed its startup tasks.
   OneShotEvent ready_;
 
   DISALLOW_COPY_AND_ASSIGN(ShellExtensionSystem);
 };
 
 }  // namespace extensions
 
 #endif  // EXTENSIONS_SHELL_BROWSER_SHELL_EXTENSION_SYSTEM_H_