Allow app_shell to run past extension manifest parsing

apps/shell/shell_extension_system.h

Index: apps/shell/shell_extension_system.h
diff --git a/apps/shell/shell_extension_system.h b/apps/shell/shell_extension_system.h
index ce74d21189d6ef3860326224dc321ee712354b45..acc34f0b573ff7d1b0778f87973500d1de4fab96 100644
--- a/apps/shell/shell_extension_system.h
+++ b/apps/shell/shell_extension_system.h
@@ -9,6 +9,10 @@
 #include "chrome/browser/extensions/extension_system.h"
 #include "extensions/common/one_shot_event.h"
 
+namespace base {
+class FilePath;
+}
+
 namespace content {
 class BrowserContext;
 }
@@ -26,6 +30,10 @@ class ShellExtensionSystem : public ExtensionSystem {
   explicit ShellExtensionSystem(content::BrowserContext* browser_context);
   virtual ~ShellExtensionSystem();
 
+  // Loads an unpacked application from a directory and attempts to launch it.
+  // Returns true on success.
+  bool LoadAndLaunchApp(const base::FilePath& app_dir);
+
   // BrowserContextKeyedService implementation:
   virtual void Shutdown() OVERRIDE;