Linux native notifications: Add server capabilities metrics

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 bfb4c9f8318b409301e8d416f3cbe24f677ed5d7..2dd7df8dcc8cd4c1eb2068f29243dacd24cdc099 100644
--- a/tools/metrics/histograms/histograms.xml
+++ b/tools/metrics/histograms/histograms.xml
@@ -25601,6 +25601,15 @@ http://cs/file:chrome/histograms.xml - but prefer this file for new entries.
   </summary>
 </histogram>
 
+<histogram name="Linux.NativeNotifications.UsingNativeNotifications"
+    enum="BooleanNativeNotifications">
+  <owner>thomasanderson@chromium.org</owner>
+  <summary>
+    Indicates if Chrome is using system notifications or the Chrome notification
+    center. (Linux only) Logged on each start up.

[Mark P, 2017/05/01 22:07:01]

This description is clear, but it doesn't sound much like the comment in the
code where it is emitted...
// Called once the connection has been set up (or not).  |success|
// indicates the connection is ready to use.

[Tom (Use chromium acct), 2017/05/01 22:35:01]

Yeah, logging this in notification_platform_bridge_linux.cc was a bit odd. 
Moved the code into native_notification_display_service.cc.  I think it makes
more sense there.

+  </summary>
+</histogram>
+
 <histogram name="Linux.SandboxStatus" enum="LinuxSandboxStatus">
   <owner>rickyz@chromium.org</owner>
   <summary>
@@ -46190,6 +46199,106 @@ http://cs/file:chrome/histograms.xml - but prefer this file for new entries.
   <summary>Time spent on specific OOBE screen.</summary>
 </histogram>
 
+<histogram name="org.Freedesktop.Notifications" enum="BooleanSupported">

[Mark P, 2017/05/01 22:07:01]

I'm reluctant to start a new group "org.".  The meaning of this isn't intuitive.
 What about Freedesktop.?

By the way, I think we encourage all histogram names to be camelcase.

[Tom (Use chromium acct), 2017/05/01 22:35:01]

Done.

+  <owner>thomasanderson@chromium.org</owner>
+  <summary>
+    Whether or not the session has a dbus object at
+    /org/Freedesktop/Notifications with interface org.Freedesktop.Notifications.
+    This indicates whether or not system notifications are supported.  (Linux
+    only) Logged on each start up.
+  </summary>
+</histogram>
+
+<histogram name="org.Freedesktop.Notifications.Capabilities.action-icons"

[Mark P, 2017/05/01 22:07:01]

I'm not sure if the dashboard supports dashes in histogram names.  Please avoid.

[Tom (Use chromium acct), 2017/05/01 22:35:01]

Done.

+    enum="BooleanSupported">
+  <owner>thomasanderson@chromium.org</owner>
+  <summary>
+    Whether the notification server has the action-icons capability.  (Linux

[Mark P, 2017/05/01 22:07:01]

Please clarify here and below that these are only recorded if there is a
notification server.  They're not logged on each start up.

[Tom (Use chromium acct), 2017/05/01 22:35:01]

Done.

+    only) Logged on each start up.
+  </summary>
+</histogram>
+
+<histogram name="org.Freedesktop.Notifications.Capabilities.actions"
+    enum="BooleanSupported">
+  <owner>thomasanderson@chromium.org</owner>
+  <summary>
+    Whether the notification server has the actions capability.  (Linux only)
+    Logged on each start up.
+  </summary>
+</histogram>
+
+<histogram name="org.Freedesktop.Notifications.Capabilities.body"
+    enum="BooleanSupported">
+  <owner>thomasanderson@chromium.org</owner>
+  <summary>
+    Whether the notification server has the body capability.  (Linux only)
+    Logged on each start up.
+  </summary>
+</histogram>
+
+<histogram name="org.Freedesktop.Notifications.Capabilities.body-hyperlinks"
+    enum="BooleanSupported">
+  <owner>thomasanderson@chromium.org</owner>
+  <summary>
+    Whether the notification server has the body-hyperlinks capability.  (Linux
+    only) Logged on each start up.
+  </summary>
+</histogram>
+
+<histogram name="org.Freedesktop.Notifications.Capabilities.body-images"
+    enum="BooleanSupported">
+  <owner>thomasanderson@chromium.org</owner>
+  <summary>
+    Whether the notification server has the body-images capability.  (Linux
+    only) Logged on each start up.
+  </summary>
+</histogram>
+
+<histogram name="org.Freedesktop.Notifications.Capabilities.body-markup"
+    enum="BooleanSupported">
+  <owner>thomasanderson@chromium.org</owner>
+  <summary>
+    Whether the notification server has the body-markup capability.  (Linux
+    only) Logged on each start up.
+  </summary>
+</histogram>
+
+<histogram name="org.Freedesktop.Notifications.Capabilities.icon-multi"
+    enum="BooleanSupported">
+  <owner>thomasanderson@chromium.org</owner>
+  <summary>
+    Whether the notification server has the icon-multi capability.  (Linux only)
+    Logged on each start up.
+  </summary>
+</histogram>
+
+<histogram name="org.Freedesktop.Notifications.Capabilities.icon-static"
+    enum="BooleanSupported">
+  <owner>thomasanderson@chromium.org</owner>
+  <summary>
+    Whether the notification server has the icon-static capability.  (Linux
+    only) Logged on each start up.
+  </summary>
+</histogram>
+
+<histogram name="org.Freedesktop.Notifications.Capabilities.persistence"
+    enum="BooleanSupported">
+  <owner>thomasanderson@chromium.org</owner>
+  <summary>
+    Whether the notification server has the persistence capability.  (Linux
+    only) Logged on each start up.
+  </summary>
+</histogram>
+
+<histogram name="org.Freedesktop.Notifications.Capabilities.sound"
+    enum="BooleanSupported">
+  <owner>thomasanderson@chromium.org</owner>
+  <summary>
+    Whether the notification server has the sound capability.  (Linux only)
+    Logged on each start up.
+  </summary>
+</histogram>
+
 <histogram name="OriginChip.Pressed">
   <obsolete>
     Deprecated with CL 731423002. OriginChip has been removed.
@@ -85556,6 +85665,11 @@ http://cs/file:chrome/histograms.xml - but prefer this file for new entries.
   <int value="1" label="Missing data in disk cache"/>
 </enum>
 
+<enum name="BooleanNativeNotifications" type="int">
+  <int value="0" label="Using Chrome notifications"/>
+  <int value="1" label="Using native notifications"/>
+</enum>
+
 <enum name="BooleanNavPreloadFinishedFirst" type="int">
   <int value="0" label="Worker preparation finished first"/>
   <int value="1" label="Navigation preload response arrived first"/>