Temporarily roll back dart dependency to work around build errors

Tracking issue https://github.com/domokit/sky_engine/issues/654

DEPS

@@ -20,7 +20,7 @@
 vars = {
   'chromium_git': 'https://chromium.googlesource.com',
   'skia_revision': '29ccdf86ab0a1649fd775c9431891bacb1391e99',
-  'dart_revision': '0210c5c035c0cb2aa8cf379abbce88ffee1e6f54',
+  'dart_revision': '38b9945cfd7cb2cc587df013d4d31ae028d99f6b',
   'dart_observatory_packages_revision': 'cdc4b3d4c15b9c0c8e7702dff127b440afbb7485',
 
   'buildtools_revision': '5215ee866bc3e8eb4a7f124212845abf4029e60b',

sky/engine/core/script/dart_controller.cc

@@ -159,6 +159,8 @@ void DartController::InstallView(View* view) {
   builtin_sky_->InstallView(view);
 }
 
+#if 0
+// Re-enable on resolution of https://github.com/domokit/sky_engine/issues/654
 static void DartController_DartStreamConsumer(
     Dart_StreamConsumer_State state,
     const char* stream_name,
@@ -177,16 +179,21 @@ static void DartController_DartStreamConsumer(
     mojo::common::BlockingCopyFromString(data, *handle);
   }
 }
-
+#endif
 void DartController::StartTracing() {
+#if 0
+// Re-enable on resolution of https://github.com/domokit/sky_engine/issues/654
   DartIsolateScope isolate_scope(dart_state()->isolate());
   DartApiScope dart_api_scope;
 
   Dart_TimelineSetRecordedStreams(DART_TIMELINE_STREAM_ALL);
+#endif
 }
 
 void DartController::StopTracing(
     mojo::ScopedDataPipeProducerHandle producer) {
+#if 0
+// Re-enable on resolution of https://github.com/domokit/sky_engine/issues/654
   DartIsolateScope isolate_scope(dart_state()->isolate());
   DartApiScope dart_api_scope;
 
@@ -195,6 +202,7 @@ void DartController::StopTracing(
   auto callback =
       reinterpret_cast<Dart_StreamConsumer>(&DartController_DartStreamConsumer);
   Dart_TimelineGetTrace(callback, &producer);
+#endif
 }
 
 } // namespace blink