Switch to putting appversion at top level of XML

This change puts appversion at the same level as buildtime, and
so it is avalable (now) for use in histogram versioning, as well
as stability versioning (or user metrics versioning).

r=huanr
Review URL: http://codereview.chromium.org/650017

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@39493 0039d316-1c4b-4281-b951-d872f2087c98
diff --git a/chrome/browser/metrics/metrics_log.cc b/chrome/browser/metrics/metrics_log.cc
index 6ddb61e5..dd4aa3f 100644
--- a/chrome/browser/metrics/metrics_log.cc
+++ b/chrome/browser/metrics/metrics_log.cc
@@ -64,6 +64,7 @@
   StartElement("log");
   WriteAttribute("clientid", client_id_);
   WriteInt64Attribute("buildtime", GetBuildTime());
+  WriteAttribute("appversion", GetVersionString());
 
   DCHECK_GE(result, 0);
 }
@@ -509,7 +510,6 @@
   OPEN_ELEMENT_FOR_SCOPE("install");
   WriteAttribute("installdate", GetInstallDate());
   WriteIntAttribute("buildid", 0);  // We're using appversion instead.
-  WriteAttribute("appversion", GetVersionString());
 }
 
 void MetricsLog::RecordEnvironment(