Revert of Move JoinString to the base namespace

extensions/browser/content_verifier.cc

 // Copyright 2014 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "extensions/browser/content_verifier.h"
 
 #include <algorithm>
 
 #include "base/files/file_path.h"
 #include "base/stl_util.h"
@@ skipping 106 matching lines @@
   // Remove the first component if it is '.' or '/' or '//'.
   const base::FilePath::StringType separators(
       base::FilePath::kSeparators, base::FilePath::kSeparatorsLength);
   if (!parts[0].empty() &&
       (parts[0] == base::FilePath::kCurrentDirectory ||
        parts[0].find_first_not_of(separators) == std::string::npos))
     parts.erase(parts.begin());
 
   // Note that elsewhere we always normalize path separators to '/' so this
   // should work for all platforms.
-  return base::FilePath(
-      base::JoinString(parts, base::FilePath::StringType(1, '/')));
+  return base::FilePath(JoinString(parts, '/'));
 }
 
 void ContentVerifier::OnExtensionLoaded(
     content::BrowserContext* browser_context,
     const Extension* extension) {
   if (shutdown_)
     return;
 
   ContentVerifierDelegate::Mode mode = delegate_->ShouldBeVerified(*extension);
   if (mode != ContentVerifierDelegate::NONE) {
@@ skipping 123 matching lines @@
           !extension_l10n_util::ShouldSkipValidation(
               locales_dir, full_path.DirName(), *all_locales))
         continue;
     }
     return true;
   }
   return false;
 }
 
 }  // namespace extensions