Fix fast user switcher appearance when empty.

chrome/browser/ui/views/profiles/profile_chooser_view.cc

Index: chrome/browser/ui/views/profiles/profile_chooser_view.cc
diff --git a/chrome/browser/ui/views/profiles/profile_chooser_view.cc b/chrome/browser/ui/views/profiles/profile_chooser_view.cc
index 296028e87a506f759d2c6baeec28f9476d33fa5a..2ad6b4a7007db8b8f43cb05c23e12988e600fce5 100644
--- a/chrome/browser/ui/views/profiles/profile_chooser_view.cc
+++ b/chrome/browser/ui/views/profiles/profile_chooser_view.cc
@@ -494,6 +494,15 @@ void ProfileChooserView::ShowBubble(
     views::BubbleBorder::Arrow arrow,
     views::BubbleBorder::BubbleAlignment border_alignment,
     Browser* browser) {
+

[Alexei Svitkine (slow), 2015/02/19 22:24:28]

Nit: No empty line in start of function body.

[anthonyvd, 2015/02/20 15:01:31]

Done.

+  // Don't start creating the view if it would be an empty fast user switcher.
+  // This is the case when there is 0 or 1 profiles (the current one).  It has
+  // to happen here to prevent the view system from creating an empty container.
+  if (view_mode == profiles::BUBBLE_VIEW_MODE_FAST_PROFILE_CHOOSER &&
+      g_browser_process->profile_manager()->GetNumberOfProfiles() <= 1) {
+    return;
+  }
+
   if (IsShowing()) {
     if (tutorial_mode != profiles::TUTORIAL_MODE_NONE) {
       profile_bubble_->tutorial_mode_ = tutorial_mode;
@@ -799,7 +808,7 @@ void ProfileChooserView::ButtonPressed(views::Button* sender,
       avatar_menu_->SwitchToProfile(
           profile_match->second,
           ui::DispositionFromEventFlags(event.flags()) == NEW_WINDOW,
-          ProfileMetrics::SWITCH_PROFILE_ICON);
+          ProfileMetrics::SWITCH_PROFILE_FAST_SWITCHER);

[Mike Lerman, 2015/02/20 14:40:57]

Don't we want to send SWITCH_PROFILE_FAST_SWITCHER only if the view_mode ==
BUBBLE_BIEW_MODE_FAST_PROFILE_CHOOSER? Otherwise we can just keep using
SWITCH_PROFILE_ICON, there's no value in moving to a new bucket; the two buckets
will have the same meaning. (an update to the description in histograms.xml may
be warranted, but that's it)

[anthonyvd, 2015/02/20 15:01:31]

You're absolutely right but SWITCH_PROFILE_ICON is still used when the New
Avatar Menu flag is disabled (it logs switches from the old bubble).  I'm
separating it into a different bucket to be able to separate the two at least
until the new avatar menu is the only one available.  Does that make sense?

[Mike Lerman, 2015/02/20 15:33:59]

We can always determine whether someone's in the New Avatar world vs. the Old
Avatar world by looking at which finch experiment they're reporting in, and
separate out the histograms reporting by Finch Experiment (this can be done
either on the histograms page as a filter or the variations page on
uma.googleplex).

Keeping it together also allows us to compare usage over time, especially
comparing back to the old avatar world of yester-year.

[anthonyvd, 2015/02/20 19:06:05]

Ah! I didn't think about separating by experiment. Very good point I'll change
it back.

     } else {
       // This was a profile accounts button.
       AccountButtonIndexes::const_iterator account_match =