This reverts commit baea9bf7.

Additionally,   we let the test run on mac8 with iphonexs because the test won't run on Xcode 10.1 (mac3-7). Hence we force it to run on mac8 which currently has Xcode 10.2.

This reverts commit 67b5bdf9.

Reason: it broke device lab.

TBR: @goderbauer 

This reverts commit f1e7fe81.

This fix is in https://github.com/flutter/packages/pull/39

This reverts commit 652be88e.

This fix is in https://github.com/flutter/packages/pull/37

This reverts commit af9f424d.

Reverts flutter/flutter#39439

Reason: this passed the local device lab test on my Macbook but it failed in the actual device lab. Will investigate, fix, and reland.

TBR: @dnfield @goderbauer @tvolkert @Hixie 

For https://github.com/flutter/flutter/issues/33899

Test added:
- simple_animation_perf_ios

Test modified:
- backdrop_filter_perf_ios__timeline_summary

We'll add the CPU/GPU measurement to more iOS tests
once it's proven to be non-flaky.

* migrate from slow async io calls

* Fix plugin template

* Add test of plugin template working

This relands https://github.com/flutter/flutter/pull/35297

The followings have been done to fix the broken tests:
  1. Add `didSendFirstFrameRasterizedEvent` extension and its tests
  2. Wait for `didSendFirstFrameRasterizedEvent` instead of
     `didSendFirstFrameEvent` during start up tests
  3. Mark missed (probably newly added) start up tests as flaky

This reverts commit 68fc7231.

This should fix https://github.com/flutter/flutter/issues/31442 and https://github.com/flutter/flutter/issues/34867

This is the first step in getting esoteric devices wired
up to device lab to ensure that we can at least start Flutter
apps in profile mode on such devices.

https://github.com/flutter/flutter/issues/35838

* Introduce image_list performance benchmark that runs on jit(debug) build.

We want to track performance of debug build because ongoing work on reducing the cost of spanwing new isolate will impact jit(debug) more than it will aot(release) configurations.

* Newlines and spaces

* more ui-as-code

* address review comments

* Introduce image loading performance test.

This example reports how long it takes to load images over the network(locally spawned server).

* Add semanticsEnabled to widgetBenchmark
* Add button_matrix_app and gesture benchmark

* Add test case for Flutter Issue #27677 as a benchmark.

See https://github.com/flutter/flutter/issues/27677

I got the following results running the test on a Moto E2 which
will help us determine how much we can gain by analyzing the
operations and eliminating unnecessary repaints based on
dirty rectangles/regions.

no blurs       - avg 216.0 fps over 3 samples
blur the group - avg  22.9 fps over 3 samples
blur each txt  - avg   3.4 fps over 3 samples

* Added the new benchmark to be tracked on the dashboard.

https://github.com/dart-lang/sdk/issues/36900

* Gradle generates ELF shared libraries instead of AOT snapshots.
* `flutter build apk/appbundle` supports multiple `--target-platform` and defaults to `android-arm` and `android-arm64`.
* `flutter build apk` now has a flag called `--split-per-abi`.