Mojo EDK: Introduce MojoQueryHandleSignalsState API

mojo/edk/js/core.cc

Index: mojo/edk/js/core.cc
diff --git a/mojo/edk/js/core.cc b/mojo/edk/js/core.cc
index f3eec8cc8422ddf69ef0ba5f093a004e3b1d1d06..db9a395402c18022dbcd7fff83f428084361f6e2 100644
--- a/mojo/edk/js/core.cc
+++ b/mojo/edk/js/core.cc
@@ -35,6 +35,20 @@ MojoResult CloseHandle(gin::Handle<HandleWrapper> handle) {
   return MOJO_RESULT_OK;
 }
 
+gin::Dictionary QueryHandleSignalsState(const gin::Arguments& args,
+                                        mojo::Handle handle) {
+  gin::Dictionary dictionary = gin::Dictionary::CreateEmpty(args.isolate());
+  if (!handle.is_valid()) {
+    dictionary.Set("result", MOJO_RESULT_INVALID_ARGUMENT);
+  } else {
+    HandleSignalsState state = handle.QuerySignalsState();
+    dictionary.Set("result", MOJO_RESULT_OK);
+    dictionary.Set("satisfiedSignals", state.satisfied_signals);
+    dictionary.Set("satisfiableSignals", state.satisfiable_signals);
+  }
+  return dictionary;
+}
+
 gin::Dictionary WaitHandle(const gin::Arguments& args,
                            mojo::Handle handle,
                            MojoHandleSignals signals,
@@ -388,6 +402,7 @@ v8::Local<v8::Value> Core::GetModule(v8::Isolate* isolate) {
             // TODO(mpcomplete): Should these just be methods on the JS Handle
             // object?
             .SetMethod("close", CloseHandle)
+            .SetMethod("queryHandleSignalsState", QueryHandleSignalsState)
             .SetMethod("wait", WaitHandle)
             .SetMethod("waitMany", WaitMany)
             .SetMethod("createMessagePipe", CreateMessagePipe)