Make remaining parts of components/metrics use metrics namespace.

components/metrics/metrics_state_manager.cc

 // Copyright 2014 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.
 
 #include "components/metrics/metrics_state_manager.h"
 
 #include "base/command_line.h"
 #include "base/guid.h"
 #include "base/metrics/histogram.h"
 #include "base/metrics/sparse_histogram.h"
@@ skipping 213 matching lines @@
 
   ClientInfo client_info;
   client_info.client_id = client_id_;
   client_info.installation_date = local_state_->GetInt64(prefs::kInstallDate);
   client_info.reporting_enabled_date =
       local_state_->GetInt64(prefs::kMetricsReportingEnabledTimestamp);
   store_client_info_.Run(client_info);
 }
 
 scoped_ptr<ClientInfo> MetricsStateManager::LoadClientInfoAndMaybeMigrate() {
-  scoped_ptr<metrics::ClientInfo> client_info = load_client_info_.Run();
+  scoped_ptr<ClientInfo> client_info = load_client_info_.Run();
 
   // Prior to 2014-07, the client ID was stripped of its dashes before being
   // saved. Migrate back to a proper GUID if this is the case. This migration
   // code can be removed in M41+.
   const size_t kGUIDLengthWithoutDashes = 32U;
   if (client_info &&
       client_info->client_id.length() == kGUIDLengthWithoutDashes) {
     DCHECK(client_info->client_id.find('-') == std::string::npos);
 
     std::string client_id_with_dashes;
@@ skipping 61 matching lines @@
 
   local_state_->ClearPref(prefs::kMetricsClientID);
   local_state_->ClearPref(prefs::kMetricsLowEntropySource);
   local_state_->ClearPref(prefs::kMetricsResetIds);
 
   // Also clear the backed up client info.
   store_client_info_.Run(ClientInfo());
 }
 
 }  // namespace metrics