8371 Add a GN format presubmit. (cla: yes)

8373 Move libdart selection into its own target in //flutter/runtime. (cla: yes)

8374 [flutter_tester] Accept –icu-data-file-path (cla: yes)

8375 Allow running runtime_unittests in AOT mode. (cla: yes)

8376 Check for hover motion events in AndroidTouchProcessor (cla: yes)

8377 Handle null values in TextInputConfiguration.actionLabel JSON (cla: yes)

8379 Allow native entrypoint registration for runtime unittests. (cla: yes)

8380 Delay platform view removal to submitFrame. (cla: yes)

8381 Remove unused DartVM::IsKernelMapping (cla: yes)