add limited analysis options

* Switch ui.window.devicePixelRatio to browser dpi
* Add integration test for multi res image loading
* Update cirrus for new integration test
* update canvas golden test root transform
* Update compositing golden test with dpr transform

See https://github.com/flutter/flutter/issues/52263

TBR: @chinmaygarde

* squashing the commits together

* directory rename, project rename. addressing reviewer comments

* update cirrus file

* change tool signature

* script for fetching correct flutter version

* change cirrus yml for the script location

* change location of the script. Add it to tools

* cirrus still does not see the script. repeat path change from the previous step

* Looks like script worked correctly. do not change directory.

* change directory back to build root after scriot is run

* script runs ok. Still not able to find the bin directory. go all the way back

* still can't see the bin directory. carry the script content to cirrus.yml to debug better

* get the last commit id of the right repository

* content of the script worked in cirrus. call the script from tools

* cannot find the script under tools

* print the current path in the script to see why cirrus cannot see bin directory

* move to flutter path before running update packages

* tests run now. remove print outs

* error if the ENGINE_PATH is not set. exit the script

* addressing reviewer comments

* engine branch name on cirrus logs doesn't make sense

* fix typo

* change the directory of branch calculation

* remove extra logs

* addressing PR comments. Testing CIRRUS_CI env variable

* adding CIRRUS_CI check

This will start to collect engine benchmarks in the flutter-cirrus
Datastore for all post-submit commits.

We're using this to test how https://github.com/liyuqian/metrics_center
works. Once it's stablized, we should move metrics_center into
flutter/packages, and migrate data to flutter-infra Datastore.

Related issue: https://github.com/flutter/flutter/issues/37434

* Enable web engine unit tests on Firefox

* addressing PR comments

* addressing PR comments

* fix the version name on the lock file

* Add Firefox installing functionality to test platform. For Linux only. Refactor test platform code

* remove download.dart. Not complete for now

* uncomment firefox.dart. Adding new CL parameters.

* Licence headers added.

* adding more comments to firefox_installer

* adding test for firefox download

* address pr comments. change directory for test in .cirrus.yml

* change directory for test_web_engine_firefox_script

* removing the system test.

This fixes https://github.com/flutter/flutter/issues/38848

This reverts commit f3d04a98.

Store screenshot test output as Cirrus artifacts; do fuzzy comparison of non-matching screenshot pixels (#12274)

- Store screenshot test output as Cirrus artifacts
- Do fuzzy comparison of non-matching screenshot pixels
- Make screenshot tests fail on Cirrus

1. Various functionalities offered by this tool are now organized into commands (e.g. `felt test`, `felt check-licenses`).
2. The felt tool can now be invoked from anywhere, not necessarily from the web_ui directory.
3. This new structure helps us scale better as we add more commands (e.g. soon a `build/watch` command is coming).

This reverts commit d026bf6c.

This will have to be landed on red since it's intended to make the tree red. It can be reverted once we've resolved the ongoing regression preventing the engine->framework roll.

Halves the presubmit times.

- Add a custom `PlatformPlugin` that spins up a server waiting for test to request a screenshot.
  - When a screenshot is requested the plugin talks to Chrome via the debug port, captures a screenshot, and compares it with a golden file
- This PR also adds proper CLI for `dev/test.dart` with an `ArgParser` for future extension into a proper developer tool for the team.
  - As a first couple of features, it adds `--debug` option to launch Chrome in debug mode, a `--target` option to choose a single test to run rather than all tests, and `--shard` option to choose a subset of tests to run.

Limitations:
 - While screenshot test will run on Cirrus, they are configured to not fail on Cirrus. Need to solve Chrome version skew.
 - Stack maps do not work yet (you get stacks, but they are nonsensical)
 - When requesting a single test, build_runner builds all tests anyway
 - Nothing but desktop Chrome is supported
 - Nothing but Linux is supported
 - There's no Chrome version pinning; currently assumed stable Chrome channel

* [flutter_runner] Add common libs to the test far

* Add flutter runner test build as part of CI

sync web engine; run web engine tests

This has landed in LUCI as of https://chromium-review.googlesource.com/c/chromium/tools/build/+/1745539

This is a subset of https://github.com/flutter/engine/pull/10485.
Hopefully this doesn't significantly reduce our coverage since we
have now limited the fuchsia auto-roller frequency.

This reverts commit 16c0058f.

Our infra should be capable to run all those deleted tests as now we've throttled the Fuchsia auto-rollers.

The current throttle is 1 PR / 3 hours for the 4 rollers:
- https://cs.corp.google.com/skia/buildbot/autoroll/config/fuchsia-mac-toolchain-flutter-engine.json?l=53
- https://cs.corp.google.com/skia/buildbot/autoroll/config/fuchsia-mac-sdk-flutter-engine.json?g=0&l=53
- https://cs.corp.google.com/skia/buildbot/autoroll/config/fuchsia-linux-toolchain-flutter-engine.json?g=0&l=56
- https://cs.corp.google.com/skia/buildbot/autoroll/config/fuchsia-linux-sdk-flutter-engine.json?g=0&l=56

We're changing them to 1 PR / 12 hours: http://skbug.com/9322

We are severely resource constrained on the tryjobs. This is hindering progress on ToT due to scheduling failures and rate limits. There are no plans to requisition more resources in this infra scheme as the migration to tryjobs on LUCI is the preferred way forward. This patch removes presubmits that are somewhat redundant. Each removed presubmit and the justification is given below:

* `build_and_test_linux_opt_release`: The AOT variant is tested by `build_and_test_linux_opt_profile` (actually its replacement, see the next point).
* `build_and_test_linux_opt_profile`: When we build the host profile variant for Android, we test it as well instead of building the extra variant (since we already need a host for a target build).
* `build_and_test_android_unopt_debug`: `gen_javadoc` have been moved to the profile variant. `Roboelectric` tests have been moved to profile variant. JIT infra will be tested by the the host tests.
* ToT framework checks: These will be performed (by the autoroller)[https://autoroll.skia.org/r/flutter-engine-flutter-autoroll?tab=status] which also has a sheriff rotation. This will also avoid us having to ignore red presubmits on manual changes.

Everything else is left as-is. To be clear, this causes strictly less checks to be performed on each commit.

* [fuchsia] Make cirrus build fuchsia artifacts

* restrict to debug mode for better build times

* fix host gen_snapshot

* change buildroot version

This reverts commit 0861e0a7.

Fix for Flutter Web tests