Run clang-modernize -use-nullptr over src/extensions/.

extensions/common/manifest_handlers/permissions_parser.cc

Index: extensions/common/manifest_handlers/permissions_parser.cc
diff --git a/extensions/common/manifest_handlers/permissions_parser.cc b/extensions/common/manifest_handlers/permissions_parser.cc
index 4e12112bb094cf70546de1b1b38c6d03f3359b48..4b344941b0534925ead4b0ba09ab648696983624 100644
--- a/extensions/common/manifest_handlers/permissions_parser.cc
+++ b/extensions/common/manifest_handlers/permissions_parser.cc
@@ -107,7 +107,7 @@ bool ParseHelper(Extension* extension,
   if (!extension->manifest()->HasKey(key))
     return true;
 
-  const base::ListValue* permissions = NULL;
+  const base::ListValue* permissions = nullptr;
   if (!extension->manifest()->GetList(key, &permissions)) {
     *error = ErrorUtils::FormatErrorMessageUTF16(errors::kInvalidPermissions,
                                                  std::string());