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

chrome/browser/extensions/external_provider_impl.cc

Index: chrome/browser/extensions/external_provider_impl.cc
diff --git a/chrome/browser/extensions/external_provider_impl.cc b/chrome/browser/extensions/external_provider_impl.cc
index dea7367f7457189ae35ada7385d3b1a242171d98..7844bca135e6f2f5010e100d8bf1aab0e5fec90c 100644
--- a/chrome/browser/extensions/external_provider_impl.cc
+++ b/chrome/browser/extensions/external_provider_impl.cc
@@ -285,7 +285,7 @@
         path = base_path.Append(external_crx);
       }
 
-      base::Version version(external_version);
+      Version version(external_version);
       if (!version.IsValid()) {
         LOG(WARNING) << "Malformed extension dictionary for extension: "
                      << extension_id.c_str() << ".  Invalid version string \""
@@ -347,9 +347,8 @@
 }
 
 bool ExternalProviderImpl::GetExtensionDetails(
-    const std::string& id,
-    Manifest::Location* location,
-    scoped_ptr<base::Version>* version) const {
+    const std::string& id, Manifest::Location* location,
+    scoped_ptr<Version>* version) const {
   CHECK(BrowserThread::CurrentlyOn(BrowserThread::UI));
   CHECK(prefs_.get());
   CHECK(ready_);
@@ -369,7 +368,7 @@
       return false;
 
     if (version)
-      version->reset(new base::Version(external_version));
+      version->reset(new Version(external_version));
 
   } else {
     NOTREACHED();  // Chrome should not allow prefs to get into this state.
@@ -390,9 +389,9 @@
   if (profile_ &&
       extension->GetString(kMinProfileCreatedByVersion,
                            &min_profile_created_by_version)) {
-    base::Version profile_version(
+    Version profile_version(
         profile_->GetPrefs()->GetString(prefs::kProfileCreatedByVersion));
-    base::Version min_version(min_profile_created_by_version);
+    Version min_version(min_profile_created_by_version);
     if (min_version.IsValid() && profile_version.CompareTo(min_version) < 0) {
       unsupported_extensions->insert(extension_id);
       VLOG(1) << "Skip installing (or uninstall) external extension: "