Delete code corresponding to old UMA prefs.

chromecast/browser/metrics/cast_metrics_service_client.cc

Index: chromecast/browser/metrics/cast_metrics_service_client.cc
diff --git a/chromecast/browser/metrics/cast_metrics_service_client.cc b/chromecast/browser/metrics/cast_metrics_service_client.cc
index 51f96ccfb06426e5c39c0469c896600c40cc9d8f..c9222d59071bb8961db8ae17d11f6654281a9435 100644
--- a/chromecast/browser/metrics/cast_metrics_service_client.cc
+++ b/chromecast/browser/metrics/cast_metrics_service_client.cc
@@ -70,16 +70,9 @@ scoped_ptr< ::metrics::ClientInfo> CastMetricsServiceClient::LoadClientInfo() {
   // kMetricsIsNewClientID would be missing if either the device was just
   // FDR'ed, or it is on pre-v1.2 build.
   if (!pref_service_->GetBoolean(prefs::kMetricsIsNewClientID)) {
-    // If the old client id exists, the device must be on pre-v1.2 build,
-    // instead of just being FDR'ed.
-    if (!pref_service_->GetString(::metrics::prefs::kMetricsOldClientID)

[gfhuang, 2015/05/29 19:54:03]

can you keep this logic and just make a local 
"const char kMetricsOldClientID[] = "user_experience_metrics.client_id" in the
top of this file.

We still don't know how many pre-v1.2 devices in the fields.

[Alexei Svitkine (slow), 2015/05/29 20:13:23]

Done.

-        .empty()) {
-      // Force old client id to be regenerated. See b/9487011.
-      client_info->client_id = base::GenerateGUID();
-      pref_service_->SetBoolean(prefs::kMetricsIsNewClientID, true);
-      return client_info.Pass();
-    }
-    // else the device was just FDR'ed, pass through.
+    client_info->client_id = base::GenerateGUID();
+    pref_service_->SetBoolean(prefs::kMetricsIsNewClientID, true);
+    return client_info.Pass();
   }
 
   const std::string client_id(GetPlatformClientID(cast_service_));