Update all users of base::Version to explicitly specify the namespace, and clean up the header.

chrome/common/extensions/manifest_handlers/minimum_chrome_version_checker.cc

Index: chrome/common/extensions/manifest_handlers/minimum_chrome_version_checker.cc
diff --git a/chrome/common/extensions/manifest_handlers/minimum_chrome_version_checker.cc b/chrome/common/extensions/manifest_handlers/minimum_chrome_version_checker.cc
index a1d4e406a881d38503e189112fb7e011b4fe9692..e9d8cee3b1c1132a97c57a33b5a81db0e366527a 100644
--- a/chrome/common/extensions/manifest_handlers/minimum_chrome_version_checker.cc
+++ b/chrome/common/extensions/manifest_handlers/minimum_chrome_version_checker.cc
@@ -33,14 +33,14 @@ bool MinimumChromeVersionChecker::Parse(Extension* extension,
     return false;
   }
 
-  Version minimum_version(minimum_version_string);
+  base::Version minimum_version(minimum_version_string);
   if (!minimum_version.IsValid()) {
     *error = ASCIIToUTF16(errors::kInvalidMinimumChromeVersion);
     return false;
   }
 
   chrome::VersionInfo current_version_info;
-  Version current_version(current_version_info.Version());
+  base::Version current_version(current_version_info.Version());
   if (!current_version.IsValid()) {
     NOTREACHED();
     return false;