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

components/crash/app/crashpad_mac.mm

Index: components/crash/app/crashpad_mac.mm
diff --git a/components/crash/app/crashpad_mac.mm b/components/crash/app/crashpad_mac.mm
index 5a3eed887cfa864a272b4adeb3b5d3f1b2ee5315..962cce63e847e26ac56c14d68a8e6c8aefad3e32 100644
--- a/components/crash/app/crashpad_mac.mm
+++ b/components/crash/app/crashpad_mac.mm
@@ -158,6 +158,10 @@ void InitializeCrashpad(const std::string& process_type) {
 
   g_simple_string_dictionary = new crashpad::SimpleStringDictionary();
   crashpad_info->set_simple_annotations(g_simple_string_dictionary);
+
+  base::debug::SetCrashKeyReportingFunctions(SetCrashKeyValue, ClearCrashKey);
+  crash_reporter_client->RegisterCrashKeys();
+
   SetCrashKeyValue("ptype", browser_process ? base::StringPiece("browser")
                                             : base::StringPiece(process_type));
   SetCrashKeyValue("pid", base::StringPrintf("%d", getpid()));
@@ -171,9 +175,6 @@ void InitializeCrashpad(const std::string& process_type) {
   // the same file and line.
   base::debug::SetDumpWithoutCrashingFunction(DumpWithoutCrashing);
 
-  base::debug::SetCrashKeyReportingFunctions(SetCrashKeyValue, ClearCrashKey);
-  crash_reporter_client->RegisterCrashKeys();
-
   if (browser_process) {
     g_database =
         crashpad::CrashReportDatabase::Initialize(database_path).release();