Add UMA for the new generic permisison class

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 92633c2addce32986ea90b051fa7ce9e593d6f3c..9f8aacf5fed6cbaa851211d61bdce406424533d1 100644
--- a/tools/metrics/histograms/histograms.xml
+++ b/tools/metrics/histograms/histograms.xml
@@ -2786,6 +2786,29 @@ Therefore, the affected-histogram name has to have at least one dot in it.
   </summary>
 </histogram>
 
+<histogram name="ContentSettings.DefaultPushMessagingSetting"
+    enum="ContentSetting">
+  <owner>miguelg@chromium.org</owner>
+  <summary>
+    The default permission setting for push messages at browser start

[Mark P, 2014/07/08 20:49:03]

Often when someone says "browser start", they mean "profile open".  Are you sure
you mean browser start here?

[Miguel Garcia, 2014/07/09 11:17:19]

Yes, this was a bad merge from the CL where I moved things upstream, changed
now.

+  </summary>
+</histogram>
+
+<histogram name="ContentSettings.PermissionDenied" enum="PermissionType">
+  <owner>miguelg@google.com</owner>
+  <summary>Number of times a given permission was granted.</summary>

[Mark P, 2014/07/08 20:49:03]

What does it mean that a given permission PermissionDenied was granted?
Please rewrite.

analogous comment on both histograms below

[Miguel Garcia, 2014/07/09 11:17:19]

Done.

+</histogram>
+
+<histogram name="ContentSettings.PermissionGranted" enum="PermissionType">
+  <owner>miguelg@chromium.org</owner>
+  <summary>Number of times a given permission was granted.</summary>
+</histogram>
+
+<histogram name="ContentSettings.PermissionRequested" enum="PermissionType">
+  <owner>miguelg@chromium.org</owner>
+  <summary>Number of times a given permission was requested.</summary>
+</histogram>
+
 <histogram name="Cookie.ParsedCookieStatus" enum="ParsedCookieStatus">
   <obsolete>
     Deprecated as of 9/2013. Experiment to measure control characters in cookies
@@ -35889,6 +35912,13 @@ Therefore, the affected-histogram name has to have at least one dot in it.
   <int value="4" label="TEST_NOT_RUN"/>
 </enum>
 
+<enum name="ContentSetting" type="int">

[Mark P, 2014/07/08 20:49:03]

Can't you reuse the previous ContentSetting enum that you added yesterday?

Why is the diff showing a new entry?

[Miguel Garcia, 2014/07/09 11:17:19]

Merge conflict, should be fixed in the latest patch

+  <int value="1" label="ALLOW"/>
+  <int value="2" label="BLOCK"/>
+  <int value="3" label="ASK"/>
+  <int value="4" label="SESSION_ONLY"/>
+</enum>
+
 <enum name="ContextualSearchOptCardAction" type="int">
   <int value="0" label="Opt-in"/>
   <int value="1" label="Opt-out"/>
@@ -36175,6 +36205,9 @@ Therefore, the affected-histogram name has to have at least one dot in it.
   <int value="3" label="Primary accounts present but different"/>
 </enum>
 
+<!-- Needs to be kept in sync with PermissionType in

[Mark P, 2014/07/08 20:49:03]

Unnecessary.  Please remove.  (Every enum in this file needs to be kept in sync
with something in the code base.)

[Miguel Garcia, 2014/07/09 11:17:19]

Done.

+ permission_context_base.h -->
+
 <enum name="DllHash" type="int">
 <!-- Generated by chrome_elf/dll_hash/dll_hash_main.cc -->
 
@@ -43884,6 +43917,12 @@ Therefore, the affected-histogram name has to have at least one dot in it.
   </int>
 </enum>
 
+<enum name="PermissionType" type="int">
+  <int value="0" label="PERMISSION_UNKONWN"/>
+  <int value="1" label="PERMISSION_MIDI_SYSEX"/>
+  <int value="2" label="PERMISSION_PUSH_MESSAGING"/>
+</enum>
+
 <enum name="PhotoEditorFileType" type="int">
   <int value="0" label="jpg"/>
   <int value="1" label="png"/>