Introduce a monotonic_clock module for Mojo.js.

mojo/apps/js/mojo_runner_delegate.cc

Index: mojo/apps/js/mojo_runner_delegate.cc
diff --git a/mojo/apps/js/mojo_runner_delegate.cc b/mojo/apps/js/mojo_runner_delegate.cc
index ba9de40f1b5391ad924a0409b0859ffecfa26232..c160f167682e9c780c3c853a931f3a9dba3c3939 100644
--- a/mojo/apps/js/mojo_runner_delegate.cc
+++ b/mojo/apps/js/mojo_runner_delegate.cc
@@ -13,6 +13,7 @@
 #include "gin/try_catch.h"
 #include "mojo/apps/js/bindings/core.h"
 #include "mojo/apps/js/bindings/gl/module.h"
+#include "mojo/apps/js/bindings/monotonic_clock.h"
 #include "mojo/apps/js/bindings/support.h"
 #include "mojo/apps/js/bindings/threading.h"
 
@@ -51,6 +52,7 @@ MojoRunnerDelegate::MojoRunnerDelegate()
   AddBuiltinModule(js::Core::kModuleName, js::Core::GetModule);
   AddBuiltinModule(js::Support::kModuleName, js::Support::GetModule);
   AddBuiltinModule(mojo::js::gl::kModuleName, mojo::js::gl::GetModule);
+  AddBuiltinModule(MonotonicClock::kModuleName, MonotonicClock::GetModule);
   AddBuiltinModule(Threading::kModuleName, Threading::GetModule);
 }