1 files changed, 3 insertions, 5 deletions
diff --git a/webkit/plugins/ppapi/ppb_graphics_2d_impl.cc b/webkit/plugins/ppapi/ppb_graphics_2d_impl.cc
index 3a75e99..bbef628 100644
--- a/webkit/plugins/ppapi/ppb_graphics_2d_impl.cc
+++ b/webkit/plugins/ppapi/ppb_graphics_2d_impl.cc
@@ -285,15 +285,13 @@ void PPB_Graphics2D_Impl::ReplaceContents(PP_Resource image_data) {
 }
 
 int32_t PPB_Graphics2D_Impl::Flush(PP_CompletionCallback callback) {
+  if (!callback.func)
+    return PP_ERROR_BLOCKS_MAIN_THREAD;
+
   // Don't allow more than one pending flush at a time.
   if (HasPendingFlush())
     return PP_ERROR_INPROGRESS;
 
-  // TODO(brettw) check that the current thread is not the main one and
-  // implement blocking flushes in this case.
-  if (!callback.func)
-    return PP_ERROR_BADARGUMENT;
-
   bool nothing_visible = true;
   for (size_t i = 0; i < queued_operations_.size(); i++) {
     QueuedOperation& operation = queued_operations_[i];