Add Brand Code to UMA Uploads

chrome/common/metrics/proto/system_profile.proto

Index: chrome/common/metrics/proto/system_profile.proto
diff --git a/chrome/common/metrics/proto/system_profile.proto b/chrome/common/metrics/proto/system_profile.proto
index 3b0fe4b9c7bb54a9e6112a6aa33bef3af4be92e0..407b9f29f5412c9e64f47c1ca63d706811711222 100644
--- a/chrome/common/metrics/proto/system_profile.proto
+++ b/chrome/common/metrics/proto/system_profile.proto
@@ -11,7 +11,7 @@ option optimize_for = LITE_RUNTIME;
 
 package metrics;
 
-// Next tag: 12
+// Next tag: 13
 message SystemProfileProto {
   // The time when the client was compiled/linked, in seconds since the epoch.
   optional int64 build_timestamp = 1;
@@ -40,6 +40,11 @@ message SystemProfileProto {
   // specific.
   optional string app_version = 2;
 
+  // The brand code or distribution tag assigned to a partner, if available.
+  // Brand codes are only available on Windows.  Not every Windows install
+  // though will have a brand code.
+  optional string brand_code = 12;
+
   // The possible channels for an installation, from least to most stable.
   enum Channel {
     CHANNEL_UNKNOWN = 0;  // Unknown channel -- perhaps an unofficial build?