Remove unnecessary wrapper on DomHighResTimestamp, and clamp resolution to 1 millisecond

third_party/WebKit/LayoutTests/fast/performance/longtasktiming.html

Index: third_party/WebKit/LayoutTests/fast/performance/longtasktiming.html
diff --git a/third_party/WebKit/LayoutTests/fast/performance/longtasktiming.html b/third_party/WebKit/LayoutTests/fast/performance/longtasktiming.html
index df103266ea8992beb41f6dee65074d8f49900179..cd5f0453b1d4b345660afa0f71766cb906ec8616 100644
--- a/third_party/WebKit/LayoutTests/fast/performance/longtasktiming.html
+++ b/third_party/WebKit/LayoutTests/fast/performance/longtasktiming.html
@@ -13,8 +13,10 @@ async_test(function (t) {
                     "entryType expected to be: longtask");
                 assert_equals(entries[i].name, "same-origin-self",
                     "name expected to be: same-origin-self");
-                assert_greater_than(entries[i].duration, 50000,
+                assert_greater_than(entries[i].duration, 50,
                     "duration expected to be greater than 50ms threshold");
+                assert_equals(entries[i].startTime, Math.floor(entries[i].startTime),
+                    "startTime expected to have 1 miilisecond granularity");
             }
             observer.disconnect();
             t.done();