Enable hide animation for login screen.

chrome/browser/chromeos/login/base_login_display_host.h

Index: chrome/browser/chromeos/login/base_login_display_host.h
diff --git a/chrome/browser/chromeos/login/base_login_display_host.h b/chrome/browser/chromeos/login/base_login_display_host.h
index b06c0cb94c5a52377965d3e5f0ef5e4fef2a415d..26418f0399bebed040582892f822457c33a3871b 100644
--- a/chrome/browser/chromeos/login/base_login_display_host.h
+++ b/chrome/browser/chromeos/login/base_login_display_host.h
@@ -54,6 +54,10 @@ class BaseLoginDisplayHost : public LoginDisplayHost,
   // Creates specific WizardController.
   virtual WizardController* CreateWizardController() = 0;
 
+  // Called when the first browser window is created, but before it's
+  // ready (shown).
+  virtual void OnBrowserCreated() = 0;
+
   const gfx::Rect& background_bounds() const { return background_bounds_; }
 
  private: