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

chrome/browser/chromeos/login/screen_locker.cc

Index: chrome/browser/chromeos/login/screen_locker.cc
diff --git a/chrome/browser/chromeos/login/screen_locker.cc b/chrome/browser/chromeos/login/screen_locker.cc
index f59307b41ea1bfa47f6e33f951aedee93a636f23..39f6bdec2d05fb882ea3dc96f14eacedfac67b7d 100644
--- a/chrome/browser/chromeos/login/screen_locker.cc
+++ b/chrome/browser/chromeos/login/screen_locker.cc
@@ -32,6 +32,7 @@
 #include "chrome/browser/chromeos/language_preferences.h"
 #include "chrome/browser/chromeos/login/authenticator.h"
 #include "chrome/browser/chromeos/login/background_view.h"
+#include "chrome/browser/chromeos/login/helper.h"
 #include "chrome/browser/chromeos/login/login_performer.h"
 #include "chrome/browser/chromeos/login/login_utils.h"
 #include "chrome/browser/chromeos/login/message_bubble.h"
@@ -622,7 +623,8 @@ ScreenLocker::ScreenLocker(const UserManager::User& user)
       // http://crosbug.com/1881
       unlock_on_input_(user_.email().empty()),
       locked_(false),
-      start_time_(base::Time::Now()) {
+      start_time_(base::Time::Now()),
+      throbber_manager_(new ThrobberManager) {
   DCHECK(!screen_locker_);
   screen_locker_ = this;
 }
@@ -645,6 +647,7 @@ void ScreenLocker::Init() {
     screen_lock_view_ = new ScreenLockView(this);
     screen_lock_view_->Init();
     screen_lock_view_->SetEnabled(false);
+    StartThrobber();

[Nikita (slow), 2010/12/09 15:33:22]

As I understand this throbber is shown while ScreenLock acquires grab.
Does it work?

   } else {
     input_event_observer_.reset(new InputEventObserver(this));
     MessageLoopForUI::current()->AddObserver(input_event_observer_.get());
@@ -781,6 +784,7 @@ void ScreenLocker::Authenticate(const string16& password) {
   authentication_start_time_ = base::Time::Now();
   screen_lock_view_->SetEnabled(false);
   screen_lock_view_->SetSignoutEnabled(false);
+  StartThrobber();
 
   // If LoginPerformer instance exists,
   // initial online login phase is still active.
@@ -809,6 +813,7 @@ void ScreenLocker::EnableInput() {
   if (screen_lock_view_) {
     screen_lock_view_->SetEnabled(true);
     screen_lock_view_->ClearAndSetFocusToPassword();
+    StopThrobber();
   }
 }
 
@@ -828,6 +833,7 @@ void ScreenLocker::ShowErrorMessage(const std::wstring& message,
                                     bool sign_out_only) {
   if (sign_out_only) {
     screen_lock_view_->SetEnabled(false);
+    StartThrobber();

[Nikita (slow), 2010/12/09 15:33:22]

Why show throbber along with error bubble?

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

may be this is a bug from http://codereview.chromium.org/3583013

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

Oshima-san is right. I have automatically copied the previous behavior of the
'SetEnabled(false)' call.

Fixed.

   } else {
     EnableInput();
   }
@@ -936,6 +942,20 @@ ScreenLocker::~ScreenLocker() {
     CrosLibrary::Get()->GetScreenLockLibrary()->NotifyScreenUnlockCompleted();
 }
 
+void ScreenLocker::StartThrobber() {
+  views::Widget* widget_under_throbber =
+      screen_lock_view_->GetWidgetForThrobber();
+  if (widget_under_throbber) {
+    throbber_manager_->StartShow(widget_under_throbber,
+                                 CreateDefaultSmoothedThrobber(),
+                                 login::kThrobberRightShift);
+  }
+}
+
+void ScreenLocker::StopThrobber() {
+  throbber_manager_->Stop();
+}
+
 void ScreenLocker::SetAuthenticator(Authenticator* authenticator) {
   authenticator_ = authenticator;
 }