Add presubmit check and automatic update script for ExtensionPermission enum.

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 f2296c481a3320f86d60668e5df8eae5b28563ed..17f9be62cfbbeff7535afdc421e069ad09af0089 100644
--- a/tools/metrics/histograms/histograms.xml
+++ b/tools/metrics/histograms/histograms.xml
@@ -26239,6 +26239,8 @@ other types of suffix sets.
 </enum>
 
 <enum name="ExtensionPermission" type="int">
+<!-- Generated from ../../../extensions/common/permissions/permission_message.h -->
+
   <int value="0" label="UNKNOWN"/>
   <int value="1" label="NONE"/>
   <int value="2" label="BOOKMARKS"/>
@@ -26247,27 +26249,57 @@ other types of suffix sets.
   <int value="5" label="TABS"/>
   <int value="6" label="MANAGEMENT"/>
   <int value="7" label="DEBUGGER"/>
-  <int value="8" label="1_HOST"/>
-  <int value="9" label="2_HOSTS"/>
-  <int value="10" label="3_HOSTS"/>
-  <int value="11" label="4_OR_MORE_HOSTS"/>
-  <int value="12" label="ALL_HOSTS"/>
-  <int value="13" label="FULL_ACCESS"/>
-  <int value="14" label="CLIPBOARD"/>
-  <int value="15" label="TTS_ENGINE"/>
-  <int value="16" label="CONTENT_SETTINGS"/>
-  <int value="17" label="PRIVACY"/>
-  <int value="18" label="MANAGED_MODE"/>
-  <int value="19" label="INPUT"/>
-  <int value="20" label="AUDIO_CAPTURE"/>
-  <int value="21" label="VIDEO_CAPTURE"/>
-  <int value="22" label="DOWNLOADS"/>
-  <int value="23" label="FILE_SYSTEM_WRITE"/>
-  <int value="24" label="ALL_MEDIA_GALLERIES"/>
-  <int value="25" label="SERIAL"/>
-  <int value="26" label="SOCKET_ANY_HOST"/>
-  <int value="27" label="SOCKET_DOMAIN_HOSTS"/>
-  <int value="28" label="SOCKET_SPECIFIC_HOSTS"/>
+  <int value="8" label="DESKTOP_CAPTURE"/>

[Jói, 2014/02/26 09:07:53]

I'm not the expert on this, you should check with
tools/metrics/histograms/OWNERS, but I'm not sure it's a good idea to change
labels after the fact, since older versions will be transmitting values with
different assumed labels.

[Ilya Sherman, 2014/03/10 22:21:54]

+1.  Is this a change that you're introducing in this CL, or is this reflecting
a change that previously landed?

[ahernandez, 2014/03/13 19:11:25]

This is a change that I am introducing in this CL, but it reflects changes that
have occurred in the permission_message.h enum.

[rpaquay, 2014/03/13 20:27:46]

A couple of things:

1) It is my understanding that changing labels (say from upper case to lower
case) is not a problem *in general*, as these labels are only used for
displaying data in the histogram web site.

2) In this case *in particular*, we should *not* change the content of the
"ExtensionPermission" because we have been recording data with "wrong" enum
values in past, as explained in
https://code.google.com/p/chromium/issues/detail?id=338008.

So, I think in this case, I propose we do the following
1) Create a new enum, let's say we call it "ExtensionPermissionNew".
2) Update this CL to update that enum only
3) Don't bother with trying to convert from lower case to upper case, and store
the enum values as is.
4) We will use then use the new enum defined in 1) as part of the fix for
crbug/338008.

+  <int value="9" label="HID"/>
+  <int value="10" label="HOSTS1"/>
+  <int value="11" label="HOSTS2"/>
+  <int value="12" label="HOSTS3"/>
+  <int value="13" label="HOSTS4_OR_MORE"/>
+  <int value="14" label="HOSTS_ALL"/>
+  <int value="15" label="FULL_ACCESS"/>
+  <int value="16" label="CLIPBOARD"/>
+  <int value="17" label="TTS_ENGINE"/>
+  <int value="18" label="CONTENT_SETTINGS"/>
+  <int value="19" label="PRIVACY"/>
+  <int value="20" label="MANAGED_MODE"/>
+  <int value="21" label="INPUT"/>
+  <int value="22" label="AUDIO_CAPTURE"/>
+  <int value="23" label="VIDEO_CAPTURE"/>
+  <int value="24" label="DOWNLOADS"/>
+  <int value="25" label="FILE_SYSTEM_WRITE"/>
+  <int value="26" label="MEDIA_GALLERIES_ALL_GALLERIES_READ"/>
+  <int value="27" label="SERIAL"/>
+  <int value="28" label="SOCKET_ANY_HOST"/>
+  <int value="29" label="SOCKET_DOMAIN_HOSTS"/>
+  <int value="30" label="SOCKET_SPECIFIC_HOSTS"/>
+  <int value="31" label="BLUETOOTH"/>
+  <int value="32" label="USB"/>
+  <int value="33" label="SYSTEM_INDICATOR"/>
+  <int value="34" label="USB_DEVICE"/>
+  <int value="35" label="MEDIA_GALLERIES_ALL_GALLERIES_COPY_TO"/>
+  <int value="36" label="SYSTEM_INFO_DISPLAY"/>
+  <int value="37" label="NATIVE_MESSAGING"/>
+  <int value="38" label="SYNC_FILE_SYSTEM"/>
+  <int value="39" label="AUDIO"/>
+  <int value="40" label="FAVICON"/>
+  <int value="41" label="MUSIC_MANAGER_PRIVATE"/>
+  <int value="42" label="WEB_CONNECTABLE"/>
+  <int value="43" label="ACTIVITY_LOG_PRIVATE"/>
+  <int value="44" label="BLUETOOTH_DEVICES"/>
+  <int value="45" label="DOWNLOADS_OPEN"/>
+  <int value="46" label="NETWORKING_PRIVATE"/>
+  <int value="47" label="DECLARATIVE_WEB_REQUEST"/>
+  <int value="48" label="FILE_SYSTEM_DIRECTORY"/>
+  <int value="49" label="FILE_SYSTEM_WRITE_DIRECTORY"/>
+  <int value="50" label="SIGNED_IN_DEVICES"/>
+  <int value="51" label="WALLPAPER"/>
+  <int value="52" label="NETWORK_STATE"/>
+  <int value="53" label="HOMEPAGE"/>
+  <int value="54" label="SEARCH_PROVIDER"/>
+  <int value="55" label="STARTUP_PAGES"/>
+  <int value="56" label="MEDIA_GALLERIES_ALL_GALLERIES_DELETE"/>
+  <int value="57" label="SCREENLOCK_PRIVATE"/>
+  <int value="58" label="OVERRIDE_BOOKMARKS_UI"/>
 </enum>
 
 <enum name="ExtensionServiceVerifyAllSuccess" type="int">