Add base:: to string16 in extensions/.

extensions/common/manifest_handler.cc

Index: extensions/common/manifest_handler.cc
diff --git a/extensions/common/manifest_handler.cc b/extensions/common/manifest_handler.cc
index 4546f3283abe2d4e0ee2f4e6fd2362f5b3ea6174..ff0495c30bdf532534e387f26e06227493c13414 100644
--- a/extensions/common/manifest_handler.cc
+++ b/extensions/common/manifest_handler.cc
@@ -79,7 +79,8 @@ bool ManifestHandler::IsRegistrationFinalized() {
 }
 
 // static
-bool ManifestHandler::ParseExtension(Extension* extension, string16* error) {
+bool ManifestHandler::ParseExtension(Extension* extension,
+                                     base::string16* error) {
   return GetRegistry()->ParseExtension(extension, error);
 }
 
@@ -127,7 +128,7 @@ void ManifestHandlerRegistry::RegisterManifestHandler(
 }
 
 bool ManifestHandlerRegistry::ParseExtension(Extension* extension,
-                                             string16* error) {
+                                             base::string16* error) {
   std::map<int, ManifestHandler*> handlers_by_priority;
   for (ManifestHandlerMap::iterator iter = handlers_.begin();
        iter != handlers_.end(); ++iter) {