Speedup Observatory elements first time rendering

runtime/observatory/lib/src/elements/helpers/rendering_scheduler.dart

Index: runtime/observatory/lib/src/elements/helpers/rendering_scheduler.dart
diff --git a/runtime/observatory/lib/src/elements/helpers/rendering_scheduler.dart b/runtime/observatory/lib/src/elements/helpers/rendering_scheduler.dart
index e3e81e07c22b06d3b4f8ff2af07fc9624ffbd9fd..fd0ce522376a07a4ef9f361d5c895dd56736e841 100644
--- a/runtime/observatory/lib/src/elements/helpers/rendering_scheduler.dart
+++ b/runtime/observatory/lib/src/elements/helpers/rendering_scheduler.dart
@@ -32,6 +32,7 @@ class RenderingScheduler<T extends Renderable> implements RenderingTask {
   bool _dirty = false;
   bool _renderingScheduled = false;
   bool _notificationScheduled = false;
+  bool _firstTime = true;

[siva, 2017/08/14 22:35:01]

ditto here, _waitForBarrier = false;

[cbernaschina, 2017/08/14 23:04:14]

Done.

 
   /// Element managed by this scheduler.
   final T element;
@@ -103,7 +104,8 @@ class RenderingScheduler<T extends Renderable> implements RenderingTask {
   void scheduleRendering() {
     if (_renderingScheduled) return;
     if (!_enabled) return;
-    queue.enqueue(this);
+    queue.enqueue(this, realtime: _firstTime);
+    _firstTime = false;
     _renderingScheduled = true;
   }