Support remote Promise in renderer

atom/browser/lib/rpc-server.coffee

@@ -10,6 +10,7 @@ valueToMeta = (sender, value) ->
   meta.type = 'buffer' if Buffer.isBuffer value
   meta.type = 'value' if value is null
   meta.type = 'array' if Array.isArray value
+  meta.type = 'promise' if Promise.resolve(value) == value
 
   # Treat the arguments object as array.
   meta.type = 'array' if meta.type is 'object' and value.callee? and value.length?
@@ -29,6 +30,8 @@ valueToMeta = (sender, value) ->
     meta.members.push {name: prop, type: typeof field} for prop, field of value
   else if meta.type is 'buffer'
     meta.value = Array::slice.call value, 0
+  else if meta.type is 'promise'
+    meta.then = valueToMeta(sender, value.then.bind(value))
   else
     meta.type = 'value'
     meta.value = value

atom/renderer/api/lib/remote.coffee

@@ -44,6 +44,7 @@ metaToValue = (meta) ->
     when 'value' then meta.value
     when 'array' then (metaToValue(el) for el in meta.members)
     when 'buffer' then new Buffer(meta.value)
+    when 'promise' then Promise.resolve(then: metaToValue(meta.then))
     when 'error'
       throw new Error("#{meta.message}\n#{meta.stack}")
     else