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

chrome/browser/chromeos/profiles/profile_helper.cc

Index: chrome/browser/chromeos/profiles/profile_helper.cc
diff --git a/chrome/browser/chromeos/profiles/profile_helper.cc b/chrome/browser/chromeos/profiles/profile_helper.cc
index 5f7c3ac368d76f3391e5f5e134732dbc842b3c72..e66cd564774de3a95c68a494bdc718d0f0e7c7c6 100644
--- a/chrome/browser/chromeos/profiles/profile_helper.cc
+++ b/chrome/browser/chromeos/profiles/profile_helper.cc
@@ -295,7 +295,7 @@ user_manager::User* ProfileHelper::GetUserByProfile(Profile* profile) {
   // Now these tests will specify special flag to continue working.
   // In future those tests can get a proper CrOS configuration i.e. register
   // and login several users if they want to work with an additional profile.
-  if (CommandLine::ForCurrentProcess()->HasSwitch(
+  if (base::CommandLine::ForCurrentProcess()->HasSwitch(
           switches::kIgnoreUserProfileMappingForTests)) {
     return user_manager->GetActiveUser();
   }