Add a flag use_software_compositing to the Widget::InitParams structure.

ui/views/controls/menu/menu_host.cc

Index: ui/views/controls/menu/menu_host.cc
diff --git a/ui/views/controls/menu/menu_host.cc b/ui/views/controls/menu/menu_host.cc
index ac9d7ad3a9ea6a61b536f45e8e37fb4f0b382516..da2f127f446d173ca83b832e04dc2b9ebe5d7c24 100644
--- a/ui/views/controls/menu/menu_host.cc
+++ b/ui/views/controls/menu/menu_host.cc
@@ -52,6 +52,12 @@ void MenuHost::InitMenuHost(Widget* parent,
       Widget::InitParams::OPAQUE_WINDOW;
   params.parent = parent ? parent->GetNativeView() : NULL;
   params.bounds = bounds;
+#if defined(OS_WIN)
+  // On Windows use the software compositor to ensure that we don't block
+  // the UI thread blocking issue during command buffer creation. We can
+  // revert this change once http://crbug.com/125248 is fixed.
+  params.force_software_compositing = true;
+#endif
   Init(params);
 
   SetContentsView(contents_view);