UMA statistics for Linux password storage backend usage

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 80a267a7efc2b8cd27e7656822edd103e05e336c..e0ca7dfb4bcf569e465dfd74679c4f6b2bc18f4a 100644
--- a/tools/metrics/histograms/histograms.xml
+++ b/tools/metrics/histograms/histograms.xml
@@ -23204,6 +23204,15 @@ Therefore, the affected-histogram name has to have at least one dot in it.
   </summary>
 </histogram>
 
+<histogram name="PasswordManager.LinuxBackendStatistics">
+  <owner>dvadym@chromium.org</owner>
+  <owner>vabr@chromium.org</owner>
+  <summary>
+    Information about usage password storage backends on Linux. It also includes

[vabr (Chromium), 2015/01/27 16:15:51]

usage -> the usage of

+    if command line flag for specific backend is given.

[vabr (Chromium), 2015/01/27 16:15:51]

if -> whether a
specific -> a specific

[dvadym, 2015/01/28 11:47:40]

Done.

+  </summary>
+</histogram>
+
 <histogram name="PasswordManager.NumPasswordsDeletedByBulkDelete">
   <owner>dubroy@chromium.org</owner>
   <owner>vabr@chromium.org</owner>
@@ -50288,6 +50297,20 @@ Therefore, the affected-histogram name has to have at least one dot in it.
   <int value="2" label="Cras"/>
 </enum>
 
+<enum name="LinuxBackendUsage" type="int">
+  <int value="0" label="KDE_FLAG_KWALLET"/>
+  <int value="1" label="KDE_FLAG_PLAINTEXT"/>
+  <int value="2" label="KDE_NOFLAG_KWALLET"/>
+  <int value="3" label="KDE_NOFLAG_PLAINTEXT"/>
+  <int value="4" label="GNOME_FLAG_KEYRING"/>
+  <int value="5" label="GNOME_FLAG_LIBSECRET"/>
+  <int value="6" label="GNOME_FLAG_PLAINTEXT"/>
+  <int value="7" label="GNOME_NOFLAG_KEYRING"/>
+  <int value="8" label="GNOME_NOFLAG_LIBSECRET"/>
+  <int value="9" label="GNOME_NOFLAG_PLAINTEXT"/>
+  <int value="10" label="OTHER_PLAINTEXT"/>
+</enum>
+
 <enum name="LinuxGlibcVersion" type="int">
   <int value="0" label="Not Parseable"/>
   <int value="1" label="Unknown"/>
@@ -61830,6 +61853,7 @@ To add a new entry, add it with any value and run test to compute valid value.
   <suffix name="group_19" label="group 19"/>
   <suffix name="group_20" label="group 20"/>
   <suffix name="" label=""/>
+  <affected-histogram name="PasswordManager.LinuxBackendStatistics"/>
   <affected-histogram name="PasswordManager.ProvisionalSaveFailure"/>
   <affected-histogram
       name="PasswordManager.SavePasswordPromptDisappearedQuickly"/>