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

chrome/browser/ui/startup/default_browser_prompt.cc

Index: chrome/browser/ui/startup/default_browser_prompt.cc
diff --git a/chrome/browser/ui/startup/default_browser_prompt.cc b/chrome/browser/ui/startup/default_browser_prompt.cc
index 329da02b9dd1e516010432b5bf8e395f9e326e73..e11da719ed817251652e9d3eae9a1adbcb16d6cf 100644
--- a/chrome/browser/ui/startup/default_browser_prompt.cc
+++ b/chrome/browser/ui/startup/default_browser_prompt.cc
@@ -267,11 +267,10 @@
     const std::string disable_version_string =
         g_browser_process->local_state()->GetString(
             prefs::kBrowserSuppressDefaultBrowserPrompt);
-    const base::Version disable_version(disable_version_string);
+    const Version disable_version(disable_version_string);
     DCHECK(disable_version_string.empty() || disable_version.IsValid());
     if (disable_version.IsValid()) {
-      if (disable_version.Equals(
-              base::Version(version_info::GetVersionNumber())))
+      if (disable_version.Equals(Version(version_info::GetVersionNumber())))
         show_prompt = false;
     }
   }