Change win32k renderer lockdown histogram from local to UMA.

This regressed by accident in crrev.com/6575fb41

BUG=365160

Review URL: https://codereview.chromium.org/888403002

Cr-Commit-Position: refs/heads/master@{#314175}

content/browser/browser_main_loop.cc

@@ -1089,7 +1089,7 @@ int BrowserMainLoop::BrowserThreadsStarted() {
 #endif
 
 #if defined(OS_WIN)
-  LOCAL_HISTOGRAM_BOOLEAN("Windows.Win32kRendererLockdown",
+  UMA_HISTOGRAM_BOOLEAN("Windows.Win32kRendererLockdown",
                         IsWin32kRendererLockdownEnabled());
 #endif
   // RDH needs the IO thread to be created