Tested with the following

$ mkdir flutter_engine
$ cd flutter_engine
$ fetch flutter
$ cd src

 # Confirm the source tree and dependencies are as expected.

BUG=None
TEST=see above

Change-Id: Ie1a6653c3b76354e282688e0db50acc112794426
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/tools/depot_tools/+/3026128Reviewed-by: Dirk Pranke <dpranke@google.com>
Commit-Queue: Chinmay Garde <chinmaygarde@google.com>