Add UMA actions and histogram for the NPAPI InfoBar.

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 ef1870e17004a7b5e1289e34e3b0539f0ed112f2..e21e53ed89a8da36a532b3799bd9ea5d794af13b 100644
--- a/tools/metrics/histograms/histograms.xml
+++ b/tools/metrics/histograms/histograms.xml
@@ -29076,6 +29076,26 @@ Therefore, the affected-histogram name has to have at least one dot in it.
   <summary>Collects Flash usage data.</summary>
 </histogram>
 
+<histogram name="Plugin.NPAPIRemovalInfobar.Removed.PluginGroup"
+    enum="PluginGroup">
+  <owner>wfh@chromium.org</owner>
+  <summary>
+    The plugin group of an NPAPI plugin that is no longer supported. Recorded
+    when the NPAPI removal infobar is shown for a plugin which is no longer
+    supported.
+  </summary>
+</histogram>
+
+<histogram name="Plugin.NPAPIRemovalInfobar.RemovedSoon.PluginGroup"
+    enum="PluginGroup">
+  <owner>wfh@chromium.org</owner>
+  <summary>
+    The plugin group of an NPAPI plugin that will be unsupported soon. Recorded
+    when the NPAPI removal infobar is shown after an NPAPI plugin first loads to
+    warn the user that NPAPI support for this plugin will be removed soon.
+  </summary>
+</histogram>
+
 <histogram name="Plugin.NPAPIStatus" enum="NPAPIPluginStatus">
   <owner>wfh@chromium.org</owner>
   <summary>
@@ -59948,6 +59968,19 @@ To add a new entry, add it with any value and run test to compute valid value.
   <int value="2" label="PLUGIN_DISABLED"/>
 </enum>
 
+<enum name="PluginGroup" type="int">
+  <int value="0" label="Adobe Reader"/>
+  <int value="1" label="Java"/>
+  <int value="2" label="Quicktime"/>
+  <int value="3" label="Shockwave"/>
+  <int value="4" label="Real Player"/>
+  <int value="5" label="Silverlight"/>
+  <int value="6" label="Windows Media Player"/>
+  <int value="7" label="Google Talk"/>
+  <int value="8" label="Google Earth"/>
+  <int value="9" label="Other Plugin"/>

[Alexei Svitkine (slow), 2015/05/12 18:33:01]

Nit: I'd put this first in the list (and update the enum in C++), so that if we
ever add new entries, it won't be in the middle of the list.

[Will Harris, 2015/05/12 19:02:55]

Done. Great spot.

+</enum>
+
 <enum name="PluginListError" type="int">
   <int value="0" label="NoError"/>
   <int value="1" label="JsonInvalidEscape"/>