Let Chrome app handle Ash accelerators first if the app is launched as a window

ash/shell/shell_delegate_impl.h

Index: ash/shell/shell_delegate_impl.h
diff --git a/ash/shell/shell_delegate_impl.h b/ash/shell/shell_delegate_impl.h
index b3905e05e778415d747adad1febaee3f9eeb0f51..fb1ae04c4b0f495a79234684acafbb25bc6bf215 100644
--- a/ash/shell/shell_delegate_impl.h
+++ b/ash/shell/shell_delegate_impl.h
@@ -29,6 +29,7 @@ class ShellDelegateImpl : public ash::ShellDelegate {
   virtual void Shutdown() OVERRIDE;
   virtual void Exit() OVERRIDE;
   virtual void NewWindow(bool incognito) OVERRIDE;
+  virtual bool IsBrowserWindow(const aura::Window* window) OVERRIDE;
   virtual void Search() OVERRIDE;
   virtual void OpenFileManager() OVERRIDE;
   virtual void OpenCrosh() OVERRIDE;