Returns a dump of the application's render tree.

These now match what 2016.3 expects.

Declares a top-level getter that returns the outputs directory to which
Flutter Driver tests can write any output files. Timeline data defaults
to this directory.

* Remove the workaround that pinned args to v0.13.6
This reverts most of the changes in commit 6331b6c8
* throw exception if exit code is not an integer
* rework command infrastructure to throw ToolExit when non-zero exitCode
* convert commands to return Future<Null>
* cleanup remaining commands to use throwToolExit for non-zero exit code
* remove isUnusual exception message
* add type annotations for updated args package

Fixes #6417

If a URL is not explicitly specified by the test author, check for an
environment-specified URL before falling back to the default value.

Add an option to provide a custom description to predicate
finders. Without a custom description we default to printing the
predicate function's signature, which is not all that useful.

Use this new option in the driver extension to print the text of the
sought after tooltip.

These changes were generated by IntelliJ.

* commit intellij project metadata

* move metadata to the top level

* delete dev/intellij

Switch our pubspec.yamls to using SDK sources so that we can have consistent
source types when we depend on these packages from external packages using SDK
sources.

* Udpate to Dart `1.20.0-dev.1.0`.

Udpate to Dart `1.20.0-dev.1.0` and corresponding `analyzer` package.

* Added `--no-packages-dir`.

* Revert extension to master.

* Added ignores.

* Review nits.

* More nits.

* Driver commands for controlling the Input widget

This commit introduces two new driver commands for controlling the
material Input widget.

* setInputText(SerializableFinder finder, String text)
* submitInputText(SerializableFinder finder)

Since it is not possible to directly modify the Input widget text,
these driver commands invokes the handler functions of the Input
widget: onChanged and onSubmitted, respectively. The `submitInputText`
command returns the submitted String as a result.

* Make input command handler methods private

Addressing comments from @yjbanov.

* Fix the issue that flutter driver does not close _peer when
driver.close() is invoked.  The problem introduces the following
unexpected behavior:

  1. Launch an app using "flutter run ..." command
  2. Run the flutter driver test using "dart flutter_test.dart"

The test will not exit after running.  The problem will be solved
if _peer is closed.

* Fix formatting issue

* bump out dep on the test package

* add other pubspecs

The new version has an API change. Also, up our SDK requirements to be a
bit more realistic.

As per the recent fix to the `always_specify_types` lint (https://github.com/dart-lang/linter/issues/199), literal maps and lists are now expected to be explicitly typed.

Running that lint on the repo identifies quite a few spots to update.  This focuses on `flutter_driver` and `flutter_sprites` (somewhat arbitrarily) but the changes are fairly representative.

Note there are a number of places where I made a quick judgement on how specific to make the types.  Feedback on those is welcome.  (Especially as we move forward with more.)

*  Gallery demo start-time performance test

* Track the worst frame in perf tests

* Use backticks in "/// Returns `null` if"

* fix analysis errors

* review comments; fix test

* re-add an export for debugPrint