Move systemInfo.cpu API out out experimental namespace.

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 11029 matching lines @@
   <int value="345" label="BLUETOOTH_READ"/>
   <int value="346" label="WEBREQUESTINTERNAL_EVENTHANDLED"/>
   <int value="347" label="EVENTS_ADDRULES"/>
   <int value="348" label="CONTEXTMENUS_CREATE"/>
   <int value="349" label="MEDIAPLAYERPRIVATE_GETPLAYLIST"/>
   <int value="350" label="DOWNLOADS_ERASE"/>
   <int value="351" label="EXPERIMENTAL_RECORD_CAPTUREURLS"/>
   <int value="352" label="TTS_ISSPEAKING"/>
   <int value="353" label="BOOKMARKS_REMOVETREE"/>
   <int value="354" label="FILEBROWSERPRIVATE_SEARCHDRIVE"/>
-  <int value="355" label="EXPERIMENTAL_SYSTEMINFO_CPU_GET"/>
+  <int value="355" label="SYSTEMINFO_CPU_GET"/>

[asargent_no_longer_on_chrome, 2013/05/30 19:14:00]

I don't think you should change this here - instead you should be adding a new
entry. 

[Tim Song, 2013/05/31 01:08:35]

I think renaming should be fine. The comment above says these fields were
auto-generated from
chrome/browser/extensions/extension_function_histogram_value.h, and the order of
the enum fields are the same. The comment in
extension_function_histogram_value.h states that renaming is fine because the
index of the histogram value remains the same.

[asargent_no_longer_on_chrome, 2013/05/31 18:31:32]

As I mentioned elsewhere, I think it's actually useful data to have separate
histograms for both the old and new names. 

[Tim Song, 2013/05/31 19:29:03]

Done.

   <int value="356" label="FILEBROWSERPRIVATE_SETPREFERENCES"/>
   <int value="357" label="FONTSETTINGS_SETFONT"/>
   <int value="358" label="SOCKET_GETNETWORKLIST"/>
   <int value="359" label="BOOKMARKS_MOVE"/>
   <int value="360" label="WALLPAPERPRIVATE_MINIMIZEINACTIVEWINDOWS"/>
   <int value="361" label="STORAGE_REMOVE"/>
   <int value="362" label="AUTOTESTPRIVATE_LOGINSTATUS"/>
   <int value="363" label="TABS_CREATE"/>
   <int value="364" label="FILEBROWSERPRIVATE_CANCELDIALOG"/>
   <int value="365" label="BROWSINGDATA_REMOVECOOKIES"/>
@@ skipping 4768 matching lines @@
 <fieldtrial name="SSLResumption">
   <group name="Resume_Handshake" label="Session Resumption"/>
   <group name="Full_Handshake" label="Full"/>
   <affected-histogram name="Net.SSL_Connection_Latency"/>
   <affected-histogram name="Net.SSL_Connection_Latency_Google"/>
 </fieldtrial>
 
 </fieldtrials>
 
 </histogram-configuration>