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

extensions/common/manifest_handlers/shared_module_info.cc

Index: extensions/common/manifest_handlers/shared_module_info.cc
diff --git a/extensions/common/manifest_handlers/shared_module_info.cc b/extensions/common/manifest_handlers/shared_module_info.cc
index 99efe8828fdc9fa1c7be4aacac5ee8c1dbbce662..edac89199603c6117e1e61de79c12d4ad01afa22 100644
--- a/extensions/common/manifest_handlers/shared_module_info.cc
+++ b/extensions/common/manifest_handlers/shared_module_info.cc
@@ -183,7 +183,7 @@ bool SharedModuleInfo::Parse(const Extension* extension,
           return false;
         }
         imports_.back().minimum_version = min_version;
-        Version v(min_version);
+        base::Version v(min_version);
         if (!v.IsValid()) {
           *error = ErrorUtils::FormatErrorMessageUTF16(
               errors::kInvalidImportVersion, base::IntToString(i));