Adds plumbing to pass WebUI mojo::Handle from browser to renderer

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 8deab6120f0b8a9c331bc7fb887c7d95358cb352..c4d84605e09f153528bdf987d7650bf9a4df1431 100644
--- a/content/renderer/render_view_impl.cc
+++ b/content/renderer/render_view_impl.cc
@@ -238,6 +238,10 @@
 #include "content/renderer/media/rtc_peer_connection_handler.h"
 #endif
 
+#if defined(USE_MOJO)
+#include "content/renderer/web_ui_mojo.h"
+#endif
+
 using blink::WebAXObject;
 using blink::WebApplicationCacheHost;
 using blink::WebApplicationCacheHostClient;
@@ -3521,7 +3525,12 @@ void RenderViewImpl::OnPostMessageEvent(
 void RenderViewImpl::OnAllowBindings(int enabled_bindings_flags) {
   if ((enabled_bindings_flags & BINDINGS_POLICY_WEB_UI) &&
       !(enabled_bindings_ & BINDINGS_POLICY_WEB_UI)) {
+    // WebUIExtensionData deletes itself when we're destroyed.
     new WebUIExtensionData(this);
+#if defined(USE_MOJO)
+    // WebUIMojo deletes itself when we're destroyed.
+    new WebUIMojo(this);
+#endif
   }
 
   enabled_bindings_ |= enabled_bindings_flags;