[Multiwindow, macOS] FlutterCompositor::Present receives view_id

[dkwingsmt]

This PR propagates the multiview design from macos/FlutterCompositor::Present to macos/FlutterEngine, stopping before embedder/FlutterCompositor::present_layers_callback.

This is as far as we can get from this side without changing the embedder API.

Part of the multiwindow project (design doc).

Pre-launch Checklist

• I read the Contributor Guide and followed the process outlined there for submitting PRs.
• I read the Tree Hygiene wiki page, which explains my responsibilities.
• I read and followed the Flutter Style Guide and the C++, Objective-C, Java style guides.
• I listed at least one issue that this PR fixes in the description above.
• I added new tests to check the change I am making or feature I am adding, or Hixie said the PR is test-exempt. See testing the engine for instructions on writing and running engine tests.
• I updated/added relevant documentation (doc comments with ///).
• I signed the CLA.
• All existing and new tests are passing.

If you need help, consider asking for advice on the #hackers-new channel on Discord.

[cbracken]

[cbracken]

Hmmm - this failure looks unrelated to your patch:

[5297/5413] ACTION //flutter/lib/snapshot:generate_snapshot_bin(//build/toolchain/mac:ios_clang_x64_sim)
FAILED: gen/flutter/lib/snapshot/vm_isolate_snapshot.bin gen/flutter/lib/snapshot/vm_snapshot_instructions.bin gen/flutter/lib/snapshot/isolate_snapshot.bin gen/flutter/lib/snapshot/isolate_snapshot_instructions.bin 
vpython3 ../../build/gn_run_binary.py clang_x64/gen_snapshot --snapshot_kind=core --enable_mirrors=false --vm_snapshot_data=/Volumes/Work/s/w/ir/cache/builder/src/out/ios_debug_sim/gen/flutter/lib/snapshot/vm_isolate_snapshot.bin --vm_snapshot_instructions=/Volumes/Work/s/w/ir/cache/builder/src/out/ios_debug_sim/gen/flutter/lib/snapshot/vm_snapshot_instructions.bin --isolate_snapshot_data=/Volumes/Work/s/w/ir/cache/builder/src/out/ios_debug_sim/gen/flutter/lib/snapshot/isolate_snapshot.bin --isolate_snapshot_instructions=/Volumes/Work/s/w/ir/cache/builder/src/out/ios_debug_sim/gen/flutter/lib/snapshot/isolate_snapshot_instructions.bin /Volumes/Work/s/w/ir/cache/builder/src/out/ios_debug_sim/flutter_patched_sdk/platform_strong.dill
Can't load Kernel binary: Invalid SDK hash.

[auto-submit]

auto label is removed for flutter/engine, pr: 37391, due to - The status or check suite Mac iOS clang-tidy has failed. Please fix the issues identified (or deflake) before re-applying this label.

[cbracken]

I wonder if there's some CI bug where the framework version used is tied to roughly what framework hash was current at the time your patch's parent engine SHA was current? Maybe rebasing to tip-of-tree engine would help?