* re-enable lint unnecessary_const

* remove trailling whitespaces

* remove unnecessary const (after merge)

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

This reverts commit cc1cf13e.

See https://github.com/flutter/flutter/pull/18881#discussion_r199285256

Our first step towards https://github.com/flutter/flutter/issues/18727

fuchsia_tester.dart still assumes Dart 1. Previously, it ran tests directly
from source, flutter_platform.dart automatically runs a kernel compile when
operating in Dart 2 mode, but this assumes a functional Dart SDK is available
in the artifacts directly, and fuchsia_tester.dart mocks out the artifacts
directory with an empty temp dir.

Remaining work is:
1. Get the frontend server building as a dependency on Fuchsia.
2. Patch fuchsia_tester.dart to use a valid Dart SDK and frontend server.

This also reverts migration to Dart 2 typedef syntax.

This reverts commit 6c56bb24. (#18362)
This reverts commit 3daebd05. (#18316)

Now that Dart 1 is turned off, reapplying my change to turn on the prefer_generic_function_type_aliases analysis option, and fix all the typedefs to Dart 2 preferred syntax.

Also eliminated the unused analysis_options_repo.yaml file and turned on public_member_api_docs in analysys_options.yaml.

No logic changes, just changing the typedef syntax for all typedefs, and updating analysis options.

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.

Our style guide says the k's are not necessary, and it seems like a good idea to make all the code be consistent on this.

Only naming changes to private vars: no logic changes.

In FlutterDriver.scrollUntilVisible, pause momentarily after we kick off
the waitFor() call, in order to give that call a chance to complete
before we start scrolling if the element is on-screen.

The new values are not ready for use yet inside Google

* Roll engine to e976be13c51448f89107d082ec81e2b6731671fa

* move away from deprecated constants

This change adds Dart VM event support (listening for when a VM starts/stops by using a periodic heartbeat).

This also adds support to connect to a specific `IsolateRef` through the flutter driver, so that when an application spawns, it can immediately be driven (as shown in included example code).

We're seeing occasional test timeouts trying to call `FlutterDriver.connect()`.
Unfortunately, when the test is timed out at the test runner level, you don't
get a meaningful test failure or stack trace of where the timeout occurrred.
Your test harness also doesn't get to clean up, which can include things like
saving the device logs to see what was going on in the device.

Thus, this change adds timeouts in the places where we've most
commonly observed hangs during tests.

* spelling: accommodate

* spelling: allotted

* spelling: anonymous

* spelling: artificial

* spelling: associated

* spelling: asset

* spelling: button

* spelling: canvas

* spelling: compatibility

* spelling: coverage

* spelling: condition

* spelling: decoration

* spelling: deferring

* spelling: diameter

* spelling: direction

* spelling: displacement

* spelling: dropdown

* spelling: needing

* spelling: environment

* spelling: exited

* spelling: expansion

* spelling: explore

* spelling: families

* spelling: horizontal

* spelling: increment

* spelling: indices

* spelling: internationalization

* spelling: labrador

* spelling: localizations

* spelling: midflight

* spelling: milliseconds

* spelling: minimum

* spelling: multiple

* spelling: multiplication

* spelling: navigator

* spelling: overridden

* spelling: package

* spelling: performance

* spelling: platform

* spelling: porsche

* spelling: position

* spelling: preceded

* spelling: precede

* spelling: precedence

* spelling: print

* spelling: property

* spelling: readily

* spelling: reproducibility

* spelling: rounded

* spelling: scroll

* spelling: separate

* spelling: separator

* spelling: services

* spelling: specific

* spelling: specify

* spelling: synchronously

* spelling: through

* spelling: timeout

* spelling: triangle

* spelling: trivial

* spelling: unusual

* spelling: then

* spelling: vertically

* spelling: visible

* spelling: visited

* spelling: voice

* All lists produced by JSON parsing are List<dynamic>. If more
speficic type is required then they need to be explicitly cast, e.g.
using castFrom helper;
* Function of type (ByText) -> Finder is not a subtype of
(SerializableFinder) -> Finder because ByText is in the contravariant
position;
* In Dart 2 typed(any) should be used instead of any in mockito based
tests.

This allows the scheduler library to depend on the services library
and the painting library to depend on the scheduler library without
the services library having to depend on the scheduler library.

While I was at it I also cleaned up some of the binding logic: the
licenses logic can now be overridden (and the test library does so),
and the image cache can now be overridden as well.

* Emulate text entry in FlutterDriver

* document enterText behavior

* remove the unnecessary composint TextRange

This patch reorganises flutter_driver's lib/src directory into three
subdirectories:

* driver: sources transitively imported/exported by flutter_driver.dart,
  which defines the API used by driver tests executed on the host machine.

* extension: sources transitively imported/exported by
  driver_extension.dart, which defines the API used to instrument a
  Flutter app running on the target device for use with a driver test.

* common: sources common to both driver and extension code.

This makes rolling Flutter into repositories that use Bazel (or
Bazel-like build systems) significantly more robust, due to the simpler
glob patterns involved.

Use of this file was eliminated in e7657b94.

* clear timeline events prior to starting a new action

* trailing commas

1. We want to measure wall-clock duration for the benchmarks, as opposed
   to thread duration (e.g., waiting on a mutex should accrue time) and
   'dur' is the metric to use for that.

2. On Darwin-based systems (macOS and iOS) 'tdur' is the result of a
   mach syscall lookup to thread_info. This call returns unreliable data
   on iOS. Chromium, for example, disables thread time support entirely
   for iOS.

I got tired of drive-by spelling fixes, so I figured I'd just take care of them all at once.

This only corrects errors in the dartdocs, not regular comments, and I skipped any sample code in the dartdocs. It doesn't touch any identifiers in the dartdocs either. No code changes, just comments.

* enable lint prefer_asserts_in_initializer_lists

* enable --assert-initializer