Add explicit base namespace to string16 users.

chrome/common/extensions/permissions/chrome_permission_message_provider.h

 // Copyright 2013 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.
 
 #ifndef CHROME_COMMON_EXTENSIONS_PERMISSIONS_CHROME_PERMISSION_MESSAGE_PROVIDER_H_
 #define CHROME_COMMON_EXTENSIONS_PERMISSIONS_CHROME_PERMISSION_MESSAGE_PROVIDER_H_
 
 #include <set>
 
 #include "base/basictypes.h"
 #include "base/gtest_prod_util.h"
 #include "base/strings/string16.h"
 #include "extensions/common/permissions/permission_message_provider.h"
 
 namespace extensions {
 
 class ChromePermissionMessageProvider : public PermissionMessageProvider {
  public:
   ChromePermissionMessageProvider();
   virtual ~ChromePermissionMessageProvider();
 
   // PermissionMessageProvider implementation.
   virtual PermissionMessages GetPermissionMessages(
       const PermissionSet* permissions,
       Manifest::Type extension_type) const OVERRIDE;
-  virtual std::vector<string16> GetWarningMessages(
+  virtual std::vector<base::string16> GetWarningMessages(
       const PermissionSet* permissions,
       Manifest::Type extension_type) const OVERRIDE;
-  virtual std::vector<string16> GetWarningMessagesDetails(
+  virtual std::vector<base::string16> GetWarningMessagesDetails(
       const PermissionSet* permissions,
       Manifest::Type extension_type) const OVERRIDE;
   virtual bool IsPrivilegeIncrease(
       const PermissionSet* old_permissions,
       const PermissionSet* new_permissions,
       Manifest::Type extension_type) const OVERRIDE;
 
  private:
   // Gets the permission messages for the API permissions.
   std::set<PermissionMessage> GetAPIPermissionMessages(
@@ skipping 26 matching lines @@
       const PermissionSet* old_permissions,
       const PermissionSet* new_permissions,
       Manifest::Type extension_type) const;
 
   DISALLOW_COPY_AND_ASSIGN(ChromePermissionMessageProvider);
 };
 
 }  // namespace extensions
 
 #endif  // CHROME_COMMON_EXTENSIONS_PERMISSIONS_CHROME_PERMISSION_MESSAGE_PROVIDER_H_