8477 Add trace events for creating minikin fonts (cla: yes)

8490 Remove unused variable (cla: yes)

8496 [scenic] Remove unused mozart.internal (cla: yes)

8497 Wire up support for Dart fixtures in shell_unittests. (cla: yes)

8498 Move constant definitions out embedder.h (cla: yes)

8499 Route FlutterEventTracer events to Fuchsia tracing for Fuchsia (cla: yes)

8500 Get rid of the macro for accessing the current test name. (cla: yes)

8503 [scenic][SCN-1054] remove dangling uses of SetTranslationRH (cla: yes)