These are essentially self-inflicted race conditions. Instead of timeouts we're going to try a more verbose logging mechanism that points out when things are taking a long time.

This reverts commit 76f70810.

* Remove many timeouts.

These are essentially self-inflicted race conditions. Instead of timeouts we're going to try a more verbose logging mechanism that points out when things are taking a long time.

* Get the attach tests to pass.

* Apply review comments from Todd

* More review comment fixes

* Put back the extended timeouts here now that I know why we have them...

* enable lint unnecessary_new

* fix tests

* fix tests

* fix tests

* Fix coverage collection crash

Based on Jason's patch in https://github.com/flutter/flutter/pull/19546/

This is more or less the same but I tried to avoid using `dynamic`.

* Improve argument and variable names in flutter_platform

* Don't bother with reduce, since the order is guaranteed.

All temporary directory start with `flutter_` and have their random component separated from the name by a period, as in `flutter_test_bundle.YFYQMY`.

I've tried to find some of the places where we didn't cleanly delete temporary directories, too. This greatly reduces, though it does not entirely eliminate, the directories we leave behind when running tests, especially `flutter_tools` tests.

While I was at it I standardized on `tempDir` as the variable name for temporary directories, since it was the most common, removing occurrences of `temp` and `tmp`, among others.

Also I factored out some common code that used to catch exceptions that happen on Windows, and made more places use that pattern.

* Try to resolve an intermitted crash during coverage collection

The only theory I can come up with is that maybe the test completes
before we finish processing the standard input, so I made the test
harness wait for the observatory URL before considering whether the
test has finished or not.

Also, some code cleanup while I'm at it, e.g. avoiding using "onFoo"
for the names of methods, avoiding back-to-back switch statements with
the same values, avoiding `_` argument names, and using `?.` instead
of `if (foo != null) foo.`.

* Revert back the signature of _pipeStandardStreamsToConsole

* Also remove the other additions to this method.

We don't actually care if we're on linux, we care only if the lcov
tool is available. We check for that explicitly just below.
Additionally there is code below which indicates that lcov is available
for macOS. Before this change that code would never execute.

This will let us re-use that code from fuchsia_tester.dart.
Tested by running the stocks example tests with coverage collection before and after.
.lcov files are identical.

This avoids notifying the coverage collector that we
completed the test when in fact we timed out, which in
turn avoids a downstream exception caused by the fact
that coverage collector assumes it has a valid observatory
port by which it can gather coverage data.

Fixes https://github.com/flutter/flutter/issues/16839

Increase coverage collection timeout to 2 minutes. Leafy is hitting the limits of the previous timeout of 30 seconds for tests that touch a lot of code in the app. (#13527)

* round 3

* partially address comments

* merge

* review notes

* review

* review

* review

Currently this just prints the observatory URL as a JSON event.
Refactored the code to make this fit in.

Builds on engine fixes to #9813

Also fixes #7366

This assumes a fix to https://github.com/dart-lang/test/issues/542

The timeout added in this patch is a workaround for https://github.com/dart-lang/coverage/issues/165

* Small Flutter strong mode cleanup fixes.

These are cases where strong mode down cast composite errors
generally indicated cases that would performance or correctness
issues if Flutter code was run in a strong mode VM.

* Fix Command API so that it is always in terms of Map<String,String>.

* Fix typedef

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

Also, defer to test package for throttling (this will require a test
package update as well).

Also, add a lot more instrumentation to --verbose mode for tests, and
fix minor trivial things here and there, and add error handling in
more places.

Also, refactor how coverage works to be simpler and not use statics.

Previously, it was possible for the test harness to bail
and the test runner to complete before the platform plugin
triggered the collection of coverage data. This fixes the
race condition such that the pending coverage collection
task is recorded immediately after starting the process.

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

Previously these widget had zero test coverage. Also, improve the
coverage tooling Mac.

Using relative paths makes it easier to share lcov.info files across machines.

This patch causes us to upload a coverage report to coveralls.io.

We need https://github.com/dart-lang/coverage/issues/100 to be fixed before
this will be useful.

Fixes #2342