flutter.md

1. Make a folder somewhere that will contain engine and framework checkouts. The rest of instructions assumes that $flt points to that folder.
2. Into $flt/flutter get flutter by

   $ cd $flt
   $ git clone https://github.com/flutter/flutter

3. Add $flt/flutter/bin to your path, run flutter doctor and fix issues if any are reported.
4. Into $flt/engine get engine checkout following these instructions. Make sure to run dependency installation scripts as described there.
5. In $flt/engine/src/third_party/dart switch to master and pull upto HEAD

   $ cd $flt/engine/src/third_party/dart
   $ git checkout master
   $ git pull --rebase    

6. In $flt/engine/src do

   $ cd $flt/engine/src
   $ flutter/tools/gn --runtime-mode debug
   $ ninja -C out/host_debug
   $ flutter/tools/gn --runtime-mode release
   $ ninja -C out/host_release
   $ flutter/tools/gn --runtime-mode release --android-cpu arm64
   $ ninja -C out/android_release_arm64

7. In $flt/flutter/examples/flutter_gallery run

   $ flutter build aot --target-platform android_arm64 --local-engine android_release_arm64 --extra-gen-snapshot-options=--print_snapshot_sizes