Set a "metrics_client_id" crash key instead of "guid" on Mac OS X

components/crash/app/crash_reporter_client.cc

 // Copyright 2013 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/crash/app/crash_reporter_client.h"
 
 #include "base/files/file_path.h"
 #include "base/logging.h"
 
 namespace crash_reporter {
 
 namespace {
 
 CrashReporterClient* g_client = NULL;
 
 }  // namespace
 
 void SetCrashReporterClient(CrashReporterClient* client) {
   g_client = client;
 }
 
 CrashReporterClient* GetCrashReporterClient() {
   DCHECK(g_client);
   return g_client;
 }
 
 CrashReporterClient::CrashReporterClient() {}
 CrashReporterClient::~CrashReporterClient() {}
 
+#if !defined(OS_MACOSX)
 void CrashReporterClient::SetCrashReporterClientIdFromGUID(
     const std::string& client_guid) {
 }
+#endif
 
 #if defined(OS_WIN)
 bool CrashReporterClient::GetAlternativeCrashDumpLocation(
     base::FilePath* crash_dir) {
   return false;
 }
 
 void CrashReporterClient::GetProductNameAndVersion(
     const base::FilePath& exe_path,
     base::string16* product_name,
@@ skipping 90 matching lines @@
 #endif
 }
 #endif
 
 bool CrashReporterClient::EnableBreakpadForProcess(
     const std::string& process_type) {
   return false;
 }
 
 }  // namespace crash_reporter