Add a simple one shot and repeating timer API for Mojo.js.

gin/arguments.h

Index: gin/arguments.h
diff --git a/gin/arguments.h b/gin/arguments.h
index ec4ae80e88219d5fcb15ecb770bfdf429c672849..f7b3389d8deed9dccb28788e34f81679de49ce72 100644
--- a/gin/arguments.h
+++ b/gin/arguments.h
@@ -6,6 +6,7 @@
 #define GIN_ARGUMENTS_H_
 
 #include "base/basictypes.h"
+#include "base/logging.h"
 #include "gin/converter.h"
 #include "gin/gin_export.h"
 
@@ -58,7 +59,9 @@ class GIN_EXPORT Arguments {
 
   template<typename T>
   void Return(T val) {
-    info_->GetReturnValue().Set(ConvertToV8(isolate_, val));
+    v8::Handle<v8::Value> r(ConvertToV8(isolate_, val));
+    LOG(ERROR) << "v8 return value: " << r->Int32Value();
+    info_->GetReturnValue().Set(r);
   }
 
   v8::Handle<v8::Value> PeekNext() const;