Added keyboard shortcut on GAIA "Add User" screen to dogfood GAIA /EmbeddedSignin

chrome/browser/ui/webui/chromeos/login/gaia_screen_handler.h

Index: chrome/browser/ui/webui/chromeos/login/gaia_screen_handler.h
diff --git a/chrome/browser/ui/webui/chromeos/login/gaia_screen_handler.h b/chrome/browser/ui/webui/chromeos/login/gaia_screen_handler.h
index 29c0746c8e4068e8e472af754153b5e0c750bebb..f80c45014d9cfad4625c91c6be8e7985254c35b8 100644
--- a/chrome/browser/ui/webui/chromeos/login/gaia_screen_handler.h
+++ b/chrome/browser/ui/webui/chromeos/login/gaia_screen_handler.h
@@ -75,6 +75,9 @@ class GaiaScreenHandler : public BaseScreenHandler {
   // not loading right now.
   void ReloadGaia(bool force_reload);
 
+  // Reload gaia with embedded signin frame.
+  void SwitchToEmbeddedSignin();
+
   FrameState frame_state() const { return frame_state_; }
   net::Error frame_error() const { return frame_error_; }
 
@@ -214,6 +217,9 @@ class GaiaScreenHandler : public BaseScreenHandler {
   std::string test_pass_;
   bool test_expects_complete_login_;
 
+  // True if user pressed shortcut to enable embedded signin.
+  bool embedded_signin_enabled_by_shortcut_;
+
   // Non-owning ptr to SigninScreenHandler instance. Should not be used
   // in dtor.
   // TODO (ygorshenin@): GaiaScreenHandler shouldn't communicate with