* Ignore extraneous error messages outside of one skipped test

* Fix analysis error

When Flutter is vendored as a submodule, `.git` is a File whose contents
are a pointer to the Git directory. This change allows you to pin your
app to a certain version of Flutter via submodules.

Generate the "version" file from git tags.
Remove the old VERSION file and mentions of versions in pubspec.yaml files.
Replace the old update_versions.dart script with a new roll_dev.dart script.
Update "flutter channel".
Update "flutter upgrade", including making it transition from alpha to dev.
Update "flutter --version" and "flutter doctor".

Depends on https://github.com/flutter/engine/pull/4483

The picture may need to draw outside the bounds (specifically for shadows)

Fixes https://github.com/flutter/flutter/issues/12618

Trying to get the build green. We will have to go through skipped tests as a more long-term task.

* Identify CHeckBox and RadioButton as such

* review feedback

* Escape path separator in regexps

* Update platform_helper.dart

* Update stack_trace_test.dart

* Update stack_trace_test.dart

* Dump exceptions live when they happen when testing tests with flutter run.

* Update binding.dart

* Document Android's SemanticsAction.tap behavior

Fixes https://github.com/flutter/flutter/issues/13219.

* review comment

Fixes https://github.com/flutter/flutter/issues/2877

Code that uses dataPatterns[loc] expects it to contain Map<String, String>, not Map<String, dynamic>.

Change gen_date_localizations.dart to generate datePatterns with a more precise type and regenerate date_localizations.dart.

* Set _imageInfo to null before adding listener to new ImageStream

Fixes an edge case where switching the ImageStream to an already completed ImageStream caused the Image widget to show nothing. ImageStreamCompleter calls the listener during addListener if their image is already loaded.

* Fix whitespace

* Add test to verify correct behavior

* Added test from mravn-google's PR

Seems like we don't yet run the flutter tests on Windows, but we're
close to being able to. This makes some minor changes to make that
more possible:

 - fix the stack parsing code to support Windows paths
 - fix the tests for the stack error handling code to handle Windows paths
 - skip some tests that rely on Ahem font metrics

* Revert "Revert "Make artifact downloading more robust for flaky networks" (#13995)"

This reverts commit 33d8a035.

* Use subdirectories to organize cached files

* Fix unauthorized import

renderObject.setFlatChildren expects List<RenderBox>, not List<RenderObject>.

...especially about TextDirection.

* Clean up output directory before copying over new files

* Use standard clean task command

* JSON.decode produces Map<String, dynamic> and List<dynamic>
objects. If a more tight type is required then object needs to
be converted explicitly (see dart-lang/sdk#31876);
* Completer<dynamic> produces Future<dynamic>. In Dart 2 it is
runtime error to assign Future<dynamic> to variable of type Future<T>;

If the downloaded file is an actual SKP and not an error report, then the
default UTF-8 codec will fail to decode the SKP content

This CL also refactors common logic for RenderPhysicalModel and
RenderPhysicalShape into a base class _RenderPhysicalModelBase.

Apple encodes syslog entries using a 7-bit encoding where input UTF-8 bytes
are encoded as follows:
1. 0x00 to 0x19: non-printing range. Some ignored, some encoded as <...>.
2. 0x20 to 0x7f: as-is, with the exception of 0x5c (backslash).
3. 0x5c (backslash): octal representation \134.
4. 0x80 to 0x9f: \M^x (using control-character notation for range 0x00 to 0x40).
5. 0xa0: octal representation \240.
6. 0xa1 to 0xf7: \M-x (where x is the input byte stripped of its high-order bit).
7. 0xf8 to 0xff: unused in 4-byte UTF-8.

As there doesn't appear to be a system tool to decode these strings, we
implement here in Dart. If we're unable to decode a string (e.g.
decoding results in an invalid UTF-8 string), we fall back to emitting
the log line as-is.

Just download a Flutter ZIP bundle, unzip, and double-click on `flutter_console.bat` to get started. No PATH modifications required.

And add a test that catches these problems.