Place the spinner in the right corner of the controls window.

chrome/browser/chromeos/login/screen_locker.h

Index: chrome/browser/chromeos/login/screen_locker.h
diff --git a/chrome/browser/chromeos/login/screen_locker.h b/chrome/browser/chromeos/login/screen_locker.h
index 27e14045b260d51f62fbe2da7bd5541941ce2fdd..39c45165c3ba8c5ab0da8a9e399ffa8ee88dc48a 100644
--- a/chrome/browser/chromeos/login/screen_locker.h
+++ b/chrome/browser/chromeos/login/screen_locker.h
@@ -32,6 +32,7 @@ class LockerInputEventObserver;
 class MessageBubble;
 class MouseEventRelay;
 class ScreenLockView;
+class ThrobberManager;
 class LoginFailure;
 
 namespace test {
@@ -118,6 +119,10 @@ class ScreenLocker : public LoginStatusConsumer,
 
   virtual ~ScreenLocker();
 
+  // Starts/Stops throbber.
+  void StartThrobber();
+  void StopThrobber();

[oshima, 2010/12/09 21:52:10]

Looks like it's simpler to have these method and ThrobberManager in 
ScreenLockView than here.  What do you think?

[altimofeev, 2010/12/10 16:37:40]

I put it here because created throbber belongs to views hierarchy that differs
from the one of the ScreenLockView.

Anyway, since there is the only view that is used by ScreenLocker, I moved the
ThrobberManager to ScreenLockView, as you had suggested.

+
   // Sets the authenticator.
   void SetAuthenticator(Authenticator* authenticator);
 
@@ -203,6 +208,8 @@ class ScreenLocker : public LoginStatusConsumer,
   // The time when the authentication is started.
   base::Time authentication_start_time_;
 
+  scoped_ptr<ThrobberManager> throbber_manager_;
+
   DISALLOW_COPY_AND_ASSIGN(ScreenLocker);
 };