Allow custom security descriptors when creating named pipes on Windows.

mojo/edk/embedder/named_platform_handle_utils_posix.cc

Index: mojo/edk/embedder/named_platform_handle_utils_posix.cc
diff --git a/mojo/edk/embedder/named_platform_handle_utils_posix.cc b/mojo/edk/embedder/named_platform_handle_utils_posix.cc
index 97572c0590377b89a1128d55c904923ec0be1865..4d9e8eece0223632050c33c5b5bcaf4dcd2816cc 100644
--- a/mojo/edk/embedder/named_platform_handle_utils_posix.cc
+++ b/mojo/edk/embedder/named_platform_handle_utils_posix.cc
@@ -99,9 +99,9 @@ ScopedPlatformHandle CreateClientHandle(
   return handle;
 }
 
-ScopedPlatformHandle CreateServerHandle(const NamedPlatformHandle& named_handle,
-                                        bool enforce_uniqueness) {
-  CHECK(!enforce_uniqueness);
+ScopedPlatformHandle CreateServerHandle(
+    const NamedPlatformHandle& named_handle,
+    const CreateServerHandleOptions& options) {
   if (!named_handle.is_valid())
     return ScopedPlatformHandle();