Expose mojo bindings to subframes in layout tests.

content/renderer/render_frame_impl.cc

Index: content/renderer/render_frame_impl.cc
diff --git a/content/renderer/render_frame_impl.cc b/content/renderer/render_frame_impl.cc
index 4549db8fc745140dfaaf4e8307da3aa80b067405..eab1b5c502fb531aad0a3f793e36cb6b91d830d0 100644
--- a/content/renderer/render_frame_impl.cc
+++ b/content/renderer/render_frame_impl.cc
@@ -1112,6 +1112,9 @@ void RenderFrameImpl::Initialize() {
   if (IsMainFrame() &&
       RenderProcess::current()->GetEnabledBindings() & BINDINGS_POLICY_WEB_UI) {
     EnableMojoBindings(false /* for_layout_tests */);
+  } else if (RenderProcess::current()->GetEnabledBindings() &
+             BINDINGS_POLICY_MOJO) {
+    EnableMojoBindings(true /* for_layout_tests */);
   }
 
 #if defined(ENABLE_PLUGINS)