Implement cloud policy invalidations using the invalidation service framework.

tools/metrics/histograms/histograms.xml

 <!--
 Copyright 2013 The Chromium Authors. All rights reserved.
 Use of this source code is governed by a BSD-style license that can be
 found in the LICENSE file.
 -->
 
 <!--
 This file is used to generate a comprehensive list of Chrome histograms along
 with a detailed description for each histogram.
 
@@ skipping 2386 matching lines @@
   </summary>
 </histogram>
 
 <histogram name="Enterprise.Policy" enum="EnterprisePolicyType">
   <summary>
     Events related to fetching, saving and loading user policies, and also
     device policies on ChromeOS.
   </summary>
 </histogram>
 
+<histogram name="Enterprise.PolicyInvalidations"
+    enum="EnterprisePolicyInvalidations">
+  <summary>Events for receiving different types of invalidations.</summary>

[Ilya Sherman, 2013/07/30 01:23:16]

This summary is very vague.  This histogram is really just a boolean histogram
tracking whether or not the invalidation contained a payload or not, right? 
(Incidentally, IMO it would be nice to explain a bit further what it means for a
policy invalidation to be issued, and what it means for it to contain a payload
or not.)

[Steve Condie, 2013/07/30 06:12:31]

Done.

+</histogram>
+
 <histogram name="Enterprise.PolicyLoadStatus" enum="EnterprisePolicyLoadStatus">
   <summary>
     Load status from the policy loaders which pull policy settings from the
     underlying platform, such as Windows Group Policy.
   </summary>
 </histogram>
 
+<histogram name="Enterprise.PolicyRefresh" enum="EnterprisePolicyRefresh">
+  <summary>
+    Events measuring effectiveness of refreshing policy when invalidations are
+    received from a service.
+  </summary>
+</histogram>
+
 <histogram name="Event.CoalescedCount.Mouse">
   <summary>Number of Mouse events coalesced.</summary>
 </histogram>
 
 <histogram name="Event.CoalescedCount.Touch">
   <summary>Number of Touch events coalesced.</summary>
 </histogram>
 
 <histogram name="Event.CoalescedLatency.Mouse" units="milliseconds">
   <summary>
@@ skipping 13709 matching lines @@
   <int value="192" label="Limit device uptime by automatically rebooting"/>
   <int value="193" label="Automatically reboot after update"/>
   <int value="194" label="Public session for auto-login"/>
   <int value="195" label="Public session auto-login timer"/>
   <int value="196"
       label="Set the restriction on the fetching of the Variations seed"/>
   <int value="197" label="Idle warning delay when running on AC power"/>
   <int value="198" label="Idle warning delay when running on battery power"/>
 </enum>
 
+<enum name="EnterprisePolicyInvalidations" type="int">
+  <summary>
+    Status codes representing types of policy invalidations received.
+  </summary>

[Ilya Sherman, 2013/07/30 01:23:16]

nit: This summary section is probably not needed.  It will only ever be shown in
the dashboard on hover, so it's generally better to simple make sure that the
histogram description includes any relevant info.  Ditto below.

[Steve Condie, 2013/07/30 06:12:31]

Done.

+  <int value="0" label="PAYLOAD">The invalidation contains a payload.</int>
+  <int value="1" label="NO_PAYLOAD">The invalidation contains no payload.</int>

[Ilya Sherman, 2013/07/30 01:23:16]

nit: I'd recommend writing this simply as:

<int value="0" label="Payload"/>
<int value="1" label="No payload"/>

[Steve Condie, 2013/07/30 06:12:31]

Done.

+</enum>
+
 <enum name="EnterprisePolicyLoadStatus" type="int">
   <summary>
     Status codes produced by the policy loaders that pull policy settings from
     the platform-specific management infrastructure, such as Windows Group
     Policy.
   </summary>
   <int value="0" label="STARTED">
     Policy load attempt started. This gets logged for each policy load attempt
     to get a baseline on the number of requests, and an arbitrary number of the
     below status codes may get added in addition.
@@ skipping 11 matching lines @@
   <int value="5" label="WOW64_REDIRECTION_DISABLED">
     Trying with Wow64 redirection disabled.
   </int>
   <int value="6" label="READ_ERROR">
     Data read error, for example file reading errors.
   </int>
   <int value="7" label="TOO_BIG">Data too large to process.</int>
   <int value="8" label="PARSE_ERROR">Parse error.</int>
 </enum>
 
+<enum name="EnterprisePolicyRefresh" type="int">
+  <summary>
+    Status codes representing whether a policy was invalidated when it was
+    refreshed and whether the refresh resulted in changed policy values.
+  </summary>
+  <int value="0" label="CHANGED">
+    Policy was not invalidated; policy was changed; invalidations were enabled.
+  </int>
+  <int value="1" label="CHANGED_NO_INVALIDATIONS">
+    Policy was not invalidated; policy was changed; invalidations were disabled.
+  </int>
+  <int value="2" label="UNCHANGED">
+    Policy was not invalidated; policy was unchanged.
+  </int>
+  <int value="3" label="INVALIDATED_CHANGED">
+    Policy was invalidated; policy was changed.
+  </int>
+  <int value="4" label="INVALIDATED_UNCHANGED">
+    Policy was invalidated; policy was unchanged.
+  </int>

[Ilya Sherman, 2013/07/30 01:23:16]

Optional nit: I'd suggest labels more like "Changed, invalidations enabled",
"Changed, invalidations disabled", "Unchanged", "Invalidated, changed", and
"Invalidated, unchanged".

[Steve Condie, 2013/07/30 06:12:31]

Done.

+</enum>
+
 <enum name="EnterprisePolicyType" type="int">
   <summary>
     Result of Policy operations as defined in
     chrome/browser/policy/enterprise_metrics.h.
   </summary>
   <int value="0" label="Load Succeeded">
     A cached policy was successfully loaded from disk.
   </int>
   <int value="1" label="Load Failed">
     Reading a cached policy from disk failed.
@@ skipping 7554 matching lines @@
   <group name="Disabled" label="Neither extra webstore link is visible"/>
   <group name="FooterLink" label="Link in bottom right of footer"/>
   <group name="PlusIcon" label="Plus icon in apps page"/>
   <affected-histogram name="Extensions.AppLaunch"/>
   <affected-histogram name="NewTabPage.DefaultPageType"/>
 </fieldtrial>
 
 </fieldtrials>
 
 </histogram-configuration>