Make crash reporting client_id accessible through child_process_logging.

chrome/common/child_process_logging_mac.mm

Index: chrome/common/child_process_logging_mac.mm
diff --git a/chrome/common/child_process_logging_mac.mm b/chrome/common/child_process_logging_mac.mm
index a53b4ed032370f87f8638c182f78b1c80c119619..04f4ca4e288c0706a80c5a31c08714e3d15a1766 100644
--- a/chrome/common/child_process_logging_mac.mm
+++ b/chrome/common/child_process_logging_mac.mm
@@ -28,6 +28,10 @@ const char *kGPUVertexShaderVersionParamName = "vsver";
 static SetCrashKeyValueFuncPtr g_set_key_func;
 static ClearCrashKeyValueFuncPtr g_clear_key_func;
 
+// Account for the terminating null character.
+static const size_t kClientIdSize = 32 + 1;
+static char g_client_id[kClientIdSize];
+
 void SetCrashKeyFunctions(SetCrashKeyValueFuncPtr set_key_func,
                           ClearCrashKeyValueFuncPtr clear_key_func) {
   g_set_key_func = set_key_func;
@@ -93,6 +97,7 @@ void SetClientId(const std::string& client_id) {
   std::string str(client_id);
   ReplaceSubstringsAfterOffset(&str, 0, "-", "");
 
+  base::strlcpy(g_client_id, str.c_str(), kClientIdSize);
   if (g_set_key_func)
     SetClientIdImpl(str, g_set_key_func);
 
@@ -100,6 +105,10 @@ void SetClientId(const std::string& client_id) {
   GoogleUpdateSettings::SetMetricsId(wstr);
 }
 
+std::string GetClientId() {
+  return std::string(g_client_id);
+}
+
 void SetActiveExtensions(const std::set<std::string>& extension_ids) {
   // TODO(port)
 }