Restore kTraceStartup flag propogation to gpu process

This was accidentally removed in http://codereview.chromium.org/8491043/diff/19001/content/browser/gpu/gpu_process_host.cc

BUG=None
TEST=start browser with --trace-startup


Review URL: http://codereview.chromium.org/8912005

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@114662 0039d316-1c4b-4281-b951-d872f2087c98

content/browser/gpu/gpu_process_host.cc

@@ -570,6 +570,7 @@ bool GpuProcessHost::LaunchGpuProcess(const std::string& channel_id) {
     switches::kGpuStartupDialog,
     switches::kLoggingLevel,
     switches::kNoSandbox,
+    switches::kTraceStartup,
   };
   cmd_line->CopySwitchesFrom(browser_command_line, kSwitchNames,
                              arraysize(kSwitchNames));