Wire up Finch experiment to MojoLoading flag

content/child/runtime_features.cc

Index: content/child/runtime_features.cc
diff --git a/content/child/runtime_features.cc b/content/child/runtime_features.cc
index c2ac56ca6d5317ca7e161712793224fe40b04cfc..c4073ed116e8788728fd06978e1cab55b46df30b 100644
--- a/content/child/runtime_features.cc
+++ b/content/child/runtime_features.cc
@@ -365,6 +365,9 @@ void SetRuntimeFeaturesDefaultsAndUpdateFromArgs(
     WebRuntimeFeatures::enableWebVR(true);
   }
 
+  if (base::FeatureList::IsEnabled(features::kLoadingWithMojo))
+    WebRuntimeFeatures::enableLoadingWithMojo(true);
+
   // Enable explicitly enabled features, and then disable explicitly disabled
   // ones.
   if (command_line.HasSwitch(switches::kEnableBlinkFeatures)) {