Enable builtin Mojo JS modules in layout tests

content/renderer/render_view_impl.cc

Index: content/renderer/render_view_impl.cc
diff --git a/content/renderer/render_view_impl.cc b/content/renderer/render_view_impl.cc
index 5a694e0704a5dad92775bad6b3d5b9d1cf28c748..42e9c7e249d50f4e7f123cf2ebdb7248c803e59d 100644
--- a/content/renderer/render_view_impl.cc
+++ b/content/renderer/render_view_impl.cc
@@ -2534,6 +2534,14 @@ void RenderViewImpl::OnAllowBindings(int enabled_bindings_flags) {
       !(enabled_bindings_ & BINDINGS_POLICY_WEB_UI)) {
     // WebUIExtensionData deletes itself when we're destroyed.
     new WebUIExtensionData(this);
+  }
+
+  // Enable Mojo bindings if either WebUI or Mojo bindings are being added to
+  // the policy and neither was previously present.
+  if (!(enabled_bindings_ & (BINDINGS_POLICY_WEB_UI | BINDINGS_POLICY_MOJO)) &&
+      (enabled_bindings_flags &
+          (BINDINGS_POLICY_WEB_UI | BINDINGS_POLICY_MOJO)) &&
+      GetMainRenderFrame()) {
     // MojoBindingsController deletes itself when we're destroyed.
     new MojoBindingsController(this);
   }