For measuring the Dart thread, we care about thread duration (tdur) rather than
wall duration (dur) because we don't want to count the time when the Dart
thread is descheduled (e.g., in preference to the raster thread).
Prior to this change, these benchmarks were mostly measuring whether the OS
decided to finish the Dart thread's time slice or hand over the CPU to the
raster thread to complete the visual part of the frame. Now we actually measure
the work done on the Dart thread.
* disables all `flutter test` and `flutter drive` tests on Windows as those two commands are not fully implemented on Windows yet
* fixes other failures on Windows
As per the recent fix to the `always_specify_types` lint (https://github.com/dart-lang/linter/issues/199), literal maps and lists are now expected to be explicitly typed.
Running that lint on the repo identifies quite a few spots to update. This focuses on `flutter_driver` and `flutter_sprites` (somewhat arbitrarily) but the changes are fairly representative.
Note there are a number of places where I made a quick judgement on how specific to make the types. Feedback on those is welcome. (Especially as we move forward with more.)
