Revert "Update typedef syntax to use Function notation and turn on lint for old notation. (#18035)" (#18041)

This reverts commit 32586020.

Fixes #18028

Just changes typedef declarations, no logic changes.

The new values are not ready for use yet inside Google

* Roll engine to e976be13c51448f89107d082ec81e2b6731671fa

* move away from deprecated constants

Some file I/O is piped from OS processes and never completes,
so without havign a timeout on the recording serialzation, we
end up waiting forever on that I/O to complete.

* Revert "Revert "Add android license verification to doctor and some refactoring" (#14727)"

This reverts commit d2602947.

* Add tests, fix sdkManagerEnv and use it consistently, and rearrange Status object model

* AnsiSpinner needs to leave the cursor where it found it.

* fix tests

* Const constructor warning only shows up on windows...?

* Avoid crash if we can't find the home directory

* Make pathVarSeparator return a string in the mock

* Implement review comments

* Fix out-of-order problem on stop

Reports from that commit included:

* Doctor hanging
* Doctor prompting to install JDK
* AnsiStatus.cancel() printing elapsed time and extra newline
* Printing extra spinner character at the end of each line

* Initial version, seems to work

* Unit test for android license checker

* Cleanups

* Windows analyzer wants const.

* Refinements to timeout

* review comments

* Forgot a nit

* round 2

* deal with null futures

* review

* review

* review

* review

* Include the process' `stdout` and `stderr` when it returns a
  non-zero exit code in `runCheckedAsync()`
* Defensively catch errors in `AndroidDevice.isAppInstalled()`
  and return false

`adb` can sometimes hang, which will in turn hang the Dart isolate if
we're using `Process.runSync()`. This changes many of the `Device` methods
to return `Future<T>` in order to allow them to use the async process
methods. A future change will add timeouts to the associated calls so
that we can properly alert the user to the hung `adb` process.

This is work towards #7102, #9567

The very first time `pod install` is invoked, CocoaPods downloads the master spec repository, which takes quite a while. Before this change, the build appeared to have stalled. With this change, at least the spinner is moving.

Added `pod setup` to the install instructions for CocoaPods, so the spec repo is downloaded while setting up Flutter, instead of during the first build.

* Revert "Eliminate CocoaPods install step (#8694)"

This reverts commit f4a13bc7.

If the developer is relying on CocoaPods and hasn't done a pod install, we will do it for them. This is needed for a smooth native plugin experience, similar to what Gradle is doing on the Android side.

There's no hard dependency on CocoaPods. We only run pod install if the project uses CocoaPods, so developers are still free to use alternatives if they prefer (and if they don't want to use native plugins).

Fixes #8685
Fixes #8657
Fixes #8526

* Require CocoaPods 1.0.0 or newer.

And make sure we don't get a crash if running `pod install` fails.

* Address review feedback

If the developer is relying on CocoaPods and hasn't done a pod install,
they'll get a build failure indicating the issue.

This also avoids a hard dependency on CocoaPods in the tool and allows
developers to customize their Xcode steps to use alternatives such as
Carthage if they prefer.

Since iOS builds are CocoaPods enabled by default, we should make sure to run `pod install` to get pods wired up before building the app.

Also added a check to `flutter doctor` to verify CocoaPods is installed.

I'm passing FLUTTER_FRAMEWORK_DIR to the `pod install` command, so we can have the app's Podfile link in Flutter.framework as a pod instead of having to copy it over in xcode_backend.sh.

This adds support for a `--bug-report` flag, which is a recording
that:
  - includes the arguments that were passed to the command runner
  - is zipped up for easy attachment in Guthub issues

...now that we have generic methods, their types need to be specified too.

This ensures that accidental usages of dart:io's
file API don't creep in over time.

With this change, they're run via instance methods on an object
obtained through the context. This will allow us to substitute
that object in tests with replay/record versions to allow us to
mock out the os-layer in tests.

- [x] Remove the second full-sync on startup.
- [x] Always invoke the snapshotter to determine the minimal set of Dart sources used.
- [x] Only synchronize the *used* Dart sources to DevFS.
- [x] Detect syntax / file missing errors on the host and gate reloads / restarts.

Fixes #6283

fixes https://github.com/flutter/flutter/issues/5788

has been fully processed before completing the returned future.
This helps prevent tests that rely on stdout from being flaky.