Add a type on lazyAsJsDate

lib/runtime/dart_sdk.js

Index: lib/runtime/dart_sdk.js
diff --git a/lib/runtime/dart_sdk.js b/lib/runtime/dart_sdk.js
index 525eb91e52447c65eb37ab7cb5a5c289ece822e8..6d550eecaca66dee292f50b5e49fd5ded86cba9c 100644
--- a/lib/runtime/dart_sdk.js
+++ b/lib/runtime/dart_sdk.js
@@ -9263,7 +9263,7 @@ dart_library.library('dart_sdk', null, /* Imports */[
       return str.charCodeAt(0) == 0 ? str : str;
     }
     static getTimeZoneName(receiver) {

[Jennifer Messerly, 2016/05/25 00:30:12]

Maybe add a type here and to getTimeZoneOffsetInMinutes too? to avoid the "as"
check

-      let d = _js_helper.Primitives.lazyAsJsDate(receiver);
+      let d = _js_helper.Primitives.lazyAsJsDate(dart.as(receiver, core.DateTime));
       let match = /\((.*)\)/.exec(d.toString());
       if (match != null) return dart.as(match[dartx.get](1), core.String);
       match = /^[A-Z,a-z]{3}\s[A-Z,a-z]{3}\s\d+\s\d{2}:\d{2}:\d{2}\s([A-Z]{3,5})\s\d{4}$/.exec(d.toString());
@@ -9273,7 +9273,7 @@ dart_library.library('dart_sdk', null, /* Imports */[
       return "";
     }
     static getTimeZoneOffsetInMinutes(receiver) {

[Jacob, 2016/05/25 00:30:03]

fix arg types for this method and the one above.

-      return -_js_helper.Primitives.lazyAsJsDate(receiver).getTimezoneOffset();
+      return -_js_helper.Primitives.lazyAsJsDate(dart.as(receiver, core.DateTime)).getTimezoneOffset();
     }
     static valueFromDecomposedDate(years, month, day, hours, minutes, seconds, milliseconds, isUtc) {
       let MAX_MILLISECONDS_SINCE_EPOCH = 8640000000000000;
@@ -9309,7 +9309,7 @@ dart_library.library('dart_sdk', null, /* Imports */[
     }
     static lazyAsJsDate(receiver) {
       if (receiver.date === void 0) {
-        receiver.date = new Date(dart.dload(receiver, 'millisecondsSinceEpoch'));
+        receiver.date = new Date(receiver.millisecondsSinceEpoch);
       }
       return receiver.date;
     }
@@ -9384,7 +9384,7 @@ dart_library.library('dart_sdk', null, /* Imports */[
       getTimeZoneOffsetInMinutes: [core.int, [dart.dynamic]],
       valueFromDecomposedDate: [dart.dynamic, [dart.dynamic, dart.dynamic, dart.dynamic, dart.dynamic, dart.dynamic, dart.dynamic, dart.dynamic, dart.dynamic]],
       patchUpY2K: [dart.dynamic, [dart.dynamic, dart.dynamic, dart.dynamic]],
-      lazyAsJsDate: [dart.dynamic, [dart.dynamic]],
+      lazyAsJsDate: [dart.dynamic, [core.DateTime]],
       getYear: [dart.dynamic, [core.DateTime]],
       getMonth: [dart.dynamic, [core.DateTime]],
       getDay: [dart.dynamic, [core.DateTime]],