Allow the content client to override browser Mojo services.

content/browser/renderer_host/render_process_host_impl.cc

Index: content/browser/renderer_host/render_process_host_impl.cc
diff --git a/content/browser/renderer_host/render_process_host_impl.cc b/content/browser/renderer_host/render_process_host_impl.cc
index 0c75bb8ac0d7b0650f94d7fd9b8171414cbf6515..7e89936b6505f0681d91cbb0463af76e179cc333 100644
--- a/content/browser/renderer_host/render_process_host_impl.cc
+++ b/content/browser/renderer_host/render_process_host_impl.cc
@@ -890,6 +890,9 @@ void RenderProcessHostImpl::RegisterMojoServices() {
   mojo_application_host_->service_registry()->AddService(
       base::Bind(&PermissionServiceContext::CreateService,
                  base::Unretained(permission_service_context_.get())));
+
+  GetContentClient()->browser()->OverridePerProcessMojoServices(
+      mojo_application_host_->service_registry());
 }
 
 int RenderProcessHostImpl::GetNextRoutingID() {