base: Remove using:: declaration from version.h header.

chrome/browser/profiles/profile_impl.cc

Index: chrome/browser/profiles/profile_impl.cc
diff --git a/chrome/browser/profiles/profile_impl.cc b/chrome/browser/profiles/profile_impl.cc
index d35ab339633fbba142eb271a25d6250ac0e49874..b722a644f2c12b3e40264241fa281430d22769a5 100644
--- a/chrome/browser/profiles/profile_impl.cc
+++ b/chrome/browser/profiles/profile_impl.cc
@@ -871,8 +871,8 @@ void ProfileImpl::OnPrefsLoaded(CreateMode create_mode, bool success) {
 }
 
 bool ProfileImpl::WasCreatedByVersionOrLater(const std::string& version) {
-  Version profile_version(ChromeVersionService::GetVersion(prefs_.get()));
-  Version arg_version(version);
+  base::Version profile_version(ChromeVersionService::GetVersion(prefs_.get()));
+  base::Version arg_version(version);
   return (profile_version.CompareTo(arg_version) >= 0);
 }