UMA: Set Hardware model class on Mac.

components/metrics/metrics_log.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_log.h"
 
 #include <algorithm>
 #include <string>
 #include <vector>
 
@@ skipping 333 matching lines @@
   // Reduce granularity of the enabled_date field to nearest hour.
   system_profile->set_uma_enabled_date(RoundSecondsToHour(enabled_date));
 
   // Reduce granularity of the install_date field to nearest hour.
   system_profile->set_install_date(RoundSecondsToHour(install_date));
 
   system_profile->set_application_locale(client_->GetApplicationLocale());
 
   SystemProfileProto::Hardware* hardware = system_profile->mutable_hardware();
 
-  // By default, the hardware class is empty (i.e., unknown).
-  hardware->set_hardware_class(std::string());
+  // HardwareModelName() will return an empty string on platforms where it's
+  // not implemented or if an error occured.
+  hardware->set_hardware_class(base::SysInfo::HardwareModelName());
 
   hardware->set_cpu_architecture(base::SysInfo::OperatingSystemArchitecture());
   hardware->set_system_ram_mb(base::SysInfo::AmountOfPhysicalMemoryMB());
 #if defined(OS_WIN)
   hardware->set_dll_base(reinterpret_cast<uint64>(&__ImageBase));
 #endif
 
   SystemProfileProto::OS* os = system_profile->mutable_os();
   std::string os_name = base::SysInfo::OperatingSystemName();
 #if defined(OS_WIN)
@@ skipping 60 matching lines @@
   DCHECK(!closed_);
   closed_ = true;
 }
 
 void MetricsLog::GetEncodedLog(std::string* encoded_log) {
   DCHECK(closed_);
   uma_proto_.SerializeToString(encoded_log);
 }
 
 }  // namespace metrics