This is a partial re-application of #24669, which was
reverted due to Fuchsia breakages.

https://github.com/flutter/flutter/issues/24413

This updates the flutter tool cache to download binary files for ideviceinstaller, ios-deploy, libimobiledevice, and dynamically linked dependencies from Flutter's GCP bucket.

Move tools tests into a general.shard directory in preparation to changing how we shard tools tests (#36108)

This reverts commit 14d489ad.

This updates the flutter tool to cache binary files for ideviceinstaller, ios-deploy, libimobiledevice, and dynamically linked dependencies from Flutter's GCP bucket.

This reverts commit 49449505.

This reverts commit 3fd36200.

* fix some formatting issues

* address review comments

* fix indent

* add trailing commas on list/map/parameters

* add trailing commas on Invocation with nb of arg>1

* add commas for widget containing widgets

* add trailing commas if instantiation contains trailing comma

* revert bad change

This reverts commit 76061c4f.

This reverts commit 98971f3c.

We have a page on the Web page now.

* enable lint unnecessary_new

* fix tests

* fix tests

* fix tests

* Upgrade everything except matcher.
* Roll matcher (and test)
* Adjust tests that depend on flutter:test directly to depend on a shim
* Require use of package:test shim and remove other references to package:test

* Remove uses of deprecated constants
* Change int.parse to int.tryParse where appropriate

The new values are not ready for use yet inside Google

* Roll engine to e976be13c51448f89107d082ec81e2b6731671fa

* move away from deprecated constants