Make callers of CommandLine use it via the base:: namespace.

chrome/browser/translate/translate_service.cc

Index: chrome/browser/translate/translate_service.cc
diff --git a/chrome/browser/translate/translate_service.cc b/chrome/browser/translate/translate_service.cc
index bf8226fa05362433526cc924345956c3e447784d..03ac7a719c1bc21109b51b9972ff124af8cbba4c 100644
--- a/chrome/browser/translate/translate_service.cc
+++ b/chrome/browser/translate/translate_service.cc
@@ -96,7 +96,7 @@ bool TranslateService::IsTranslateBubbleEnabled() {
   return true;
 #elif defined(OS_MACOSX)
   // The bubble UX is experimental on Mac OS X.
-  return CommandLine::ForCurrentProcess()->HasSwitch(
+  return base::CommandLine::ForCurrentProcess()->HasSwitch(
       switches::kEnableTranslateNewUX);
 #else
   // The bubble UX is not implemented on other platforms.