Fixes #4261

* refactor _run to runCmd

* replace requiresProjectRoot getter with call to commandValidator

* replace requiresDevice getter with call to findTargetDevice

* trace command requires a debug connection, not a device

* inline androidOnly getter

* rename command methods to verifyTheRunCmd and runCmd

* move common verification into BuildSubCommand

* rename deviceForCommand to device

* rename methods to verifyThenRunCommand and runCommand

... in place of manual process wrangling.

Fixes flutter drive breakage introduced in d2fda677.

* improve device matching error message
fixes https://github.com/flutter/flutter/issues/5675

* This reverts commit 5e7e7b6e.

* default to lib/main.dart

This reverts commit 32ad81c8.

This prevents multiple simultaneous runs of the analyzer from stomping
over each other (e.g. multiple runs of 'update-packages'). Certain
long-lived commands (like analyze, run, logs) are exempted once they've
done enough work to be safe from most stomping action.

This still doesn't make us entirely safe from craziness, e.g. if you're
half way through an 'update-packages' run and you call 'git pull', who
knows what state you'll end up in. But there's only so much one can do.

Fixes https://github.com/flutter/flutter/issues/2762

* refactor the --resident run option into a separate file

* update daemon to run --resident apps

* re-plumbing daemon start

* send app logs

* update tests

* review changes

* fix test runner

* remove PackageMap.createGlobalInstance; rely on the ctor

* review comments

* run pub get (w/ symlinks) for flutter drive

* review comments

* modernize `flutter drive` w.r.t. debug/profil/release options

* make error message prettier

Wire up ios-profile and ios-release. Switching between debug, profile and release starts the build process from scratch. (#4063)

This also fixes some related problems affecting "flutter run":
  * FLXes built during AndroidDevice.startApp need to match the build mode
  * APKs should always be rebuilt if the build mode uses AOT compilation

* rename service_protocol.dart to protocol_discovery.dart

* add a wrapper around the obs. protocol

* use json-rpc in run

* consolidate obs. code; implement flutter run --benchmark

* review comments

Artifacts from local engine builds will be found based on the --local-engine flag

Host tools can be found in the artifact cache directory for the host platform.
If a developer wants to use a local engine build instead, then provide an
--engine-build flag that selects the specific engine build variant.

* fix analysis errors

* review comments; fix test

* re-add an export for debugPrint

* rework flutter run

* fix npe with --debug-port

* connect to obs and exit when that conneciton closes

* update todos

* download android-arm-deploy

* wire up --deploy to android-arm-deploy

* fix interpolation

* use the new cache code to locate more artifacts

* add todo

* review comments

When @jason-simons added the diagnostic server on Android this
happened to conflict with flutter drive's usage of 8182.

We really should fix both of these port users to be dynamic
but this fixes https://github.com/flutter/flutter/issues/3291
for now.

@yjbanov

* add a --deploy flag to build apk

* update command description

* use an enum instead of a bool param for build variants

* rename buildForDeploy flag to buildVariant

* review comments

Add a command that can capture a Skia picture of a Flutter frame and send it to a file or skiaserve debugger (#3165)

The way we pick observatory port # has changed and we have broken
logic that handles port 8181. To fix the buildbot, switch to port
8182. We can later figure out what we want to do when we clean up
port handling.

The old VM extention for extracting the timeline data is gone.
Switch to the new '_getVMTimeline' API.

Driver returns exit code 0 even when tests fail. This commit fixes it by
propagating the exit code set by `package:test`.