tools/metrics/histograms/histograms.xml

Index: tools/metrics/histograms/histograms.xml
diff --git a/tools/metrics/histograms/histograms.xml b/tools/metrics/histograms/histograms.xml
index 78ddae6d05f1f1581dd655b7f28ff1aa3ede9603..671a026b11a84336b428bd115db6aecac77b33f8 100644
--- a/tools/metrics/histograms/histograms.xml
+++ b/tools/metrics/histograms/histograms.xml
@@ -6582,6 +6582,27 @@ other types of suffix sets.
   </summary>
 </histogram>
 
+<histogram name="MultiProfile.SigninUser" enum="SigninUserAction">

[Ilya Sherman, 2013/09/28 00:29:35]

nit: I'd suggest naming this histogram something more like
"MultiProfile.SignInAccessPoint".

[Tim Song, 2013/09/28 01:35:13]

Done. I think SigninUserUIPath should better describe what we're recording.

+  <summary>
+    The number of times a user is signed into a multiprofile session on ChromeOS
+    for each UI flow (eg. system tray, browser frame).

[Ilya Sherman, 2013/09/28 00:29:35]

nit: I'd rephrase this description to something a little clearer.  One
suggestion, that you should feel free to improve upon: "The frequency with which
each UI access point is used for signing into a multiprofile session on
ChromeOS.  Access points include the system tray and the user account switcher
on the browser frame."

[Tim Song, 2013/09/28 01:35:13]

Done.

+  </summary>
+</histogram>
+
+<histogram name="MultiProfile.SwitchActiveUser" enum="SwitchActiveUserAction">

[Ilya Sherman, 2013/09/28 00:29:35]

nit: Since the enums are highly related, it would be nice if they shared a
common prefix.

[Tim Song, 2013/09/28 01:35:13]

Done.

+  <summary>
+    The number of times the active user switched in a multiprofile session on
+    ChromeOS for each UI flow (eg. system tray, keyboard shortcut).
+  </summary>
+</histogram>
+
+<histogram name="Multiprofile.UserCount">
+  <summary>
+    The number of users simultaneously signed into a multiprofile session on
+    ChromeOS.

[Ilya Sherman, 2013/09/28 00:29:35]

Please document when this will be recorded.

[Tim Song, 2013/09/28 01:35:13]

Done.

+  </summary>
+</histogram>
+
 <histogram name="Navigation.MainFrameScheme" enum="NavigationScheme">
   <summary>The scheme of the URL for each main-frame navigation.</summary>
 </histogram>
@@ -25507,6 +25528,11 @@ other types of suffix sets.
   <int value="2" label="Dismiss"/>
 </enum>
 
+<enum name="SigninUserAction" type="int">
+  <int value="0" label="SIGNIN_USER_BY_TRAY"/>
+  <int value="1" label="SIGNIN_USER_BY_BROWSER_FRAME"/>

[Ilya Sherman, 2013/09/28 00:29:35]

These labels are human-readable strings, so it would be nice to format them to
be more human-friendly.  Suggestions: "System tray", "Browser frame"

[Tim Song, 2013/09/28 01:35:13]

Done.

+</enum>
+
 <enum name="SimpleCache.EntryCreatedAndStream2Omitted" type="int">
   <int value="0" label="Stream 2 file was present"/>
   <int value="1" label="Empty stream 2 file was omitted"/>
@@ -26307,6 +26333,11 @@ other types of suffix sets.
   <int value="3" label="Attempted"/>
 </enum>
 
+<enum name="SwitchActiveUserAction" type="int">
+  <int value="0" label="SWITCH_ACTIVE_USER_BY_TRAY"/>
+  <int value="1" label="SWITCH_ACTIVE_USER_BY_ACCELERATOR"/>
+</enum>
+
 <enum name="TabRestoreResult" type="int">
   <int value="0" label="Failure (other)"/>
   <int value="1" label="Success"/>