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

chrome/browser/extensions/updater/extension_updater_unittest.cc

Index: chrome/browser/extensions/updater/extension_updater_unittest.cc
diff --git a/chrome/browser/extensions/updater/extension_updater_unittest.cc b/chrome/browser/extensions/updater/extension_updater_unittest.cc
index 7c2786247f429c187e6ec25cce46b018392094d4..8541b771dbc36449e8669d16403c46b7201c8cd5 100644
--- a/chrome/browser/extensions/updater/extension_updater_unittest.cc
+++ b/chrome/browser/extensions/updater/extension_updater_unittest.cc
@@ -434,7 +434,7 @@ void SetupPendingExtensionManagerForTest(
         PendingExtensionInfo(id,
                              std::string(),
                              update_url,
-                             Version(),
+                             base::Version(),
                              should_allow_install,
                              kIsFromSync,
                              Manifest::INTERNAL,
@@ -1168,7 +1168,7 @@ class ExtensionUpdaterTest : public testing::Test {
 
     std::string id = "aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa";
     std::string hash;
-    Version version("0.0.1");
+    base::Version version("0.0.1");
     std::set<int> requests;
     requests.insert(0);
     scoped_ptr<ExtensionDownloader::ExtensionFetch> fetch(
@@ -1278,7 +1278,7 @@ class ExtensionUpdaterTest : public testing::Test {
     GURL test_url(base::StringPrintf("%s/extension.crx", url_prefix.c_str()));
     std::string id = "aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa";
     std::string hash;
-  Version version("0.0.1");
+    base::Version version("0.0.1");
     std::set<int> requests;
     requests.insert(0);
     scoped_ptr<ExtensionDownloader::ExtensionFetch> fetch(