This will help us know for sure exactly which sub-script erred.

* Have sanity check pass on old and new versions of flutter

* update the font used for docs.flutter.io

* update to use the flutter primary color

* update the header background color

* Fix tests to use Ahem, and helpful changes around that

- Fix fonts that had metric-specific behaviours.

- LiveTestWidgetsFlutterBinding.allowAllFrames has been renamed
  to LiveTestWidgetsFlutterBinding.framePolicy.

- LiveTestWidgetsFlutterBinding now defaults to using a frame policy
  that pumps slightly more frames, to animate the pointer crosshairs.

- Added "flutter run --use-test-fonts" to enable Ahem on devices.

- Changed how idle() works to be more effective in live mode.

- Display the test name in live mode (unless ahem fonts are enabled).

- Added a toString to TextSelectionPoint.

- Style nit fixes.

* Roll engine to get Ahem changes.

* Update tests for dartdoc changes.

* Fix flutter_tools tests

Fixes https://github.com/flutter/flutter/issues/7974

Fixes https://github.com/flutter/flutter/issues/7963

We were checking similar things in two places. Now we check everything in one
place.

Now that dart-lang/dartdoc#1236 is fixed.

See https://github.com/flutter/flutter/pull/6861

This silences all but two of the warnings from https://travis-ci.org/flutter/flutter/builds/176055550

One of the silenced warnings was a genuine code error.

Some of the others were correct but there was no way for the analyzer to know, and I worked around them.

The remainder are problems with the analyzer, specifically https://github.com/dart-lang/sdk/issues/27827 and https://github.com/dart-lang/sdk/issues/27504.

* 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

...by reverting us to an earlier dartdoc package.

Also I added a sanity test to make sure that we don't regress this again.

These aren't needed anymore.

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.

* peg dartdoc to a specific version

* add some documentation

* apply the fix to dev/bots/docs instead

`flutter test` now has a `--merge-coverage` flag that can be used to merge
coverage data from previous runs, enabling faster iteration cycles.

We now have 100% coverage of animation.dart and animation_controller.dart.
Also, add some basic tools for working with lcov files. These tools need much
more polish.

* gracefully handle generating docs twice

* silently handle if directory doesn't exist

* put an index at root of API docs bucket

* ignore all of dev/docs/doc dir, fix a bug, remove private names from doc gen script

* tweaks from review

* updates from the flutter gallery rename

* rename ids to io.flutter.gallery

The same can now be achieved using `flutter run --trace-startup --no-checked`.

* Revert "Revert "Mega gallery (#3647)" (#3659)"

This reverts commit ea62d31f.

* fix the dev/dartdoc.dart script

This reverts commit 9497fb56.

This patch broke the dartdoc step on the bots.

* working on a large benchmark app

* build a 100k saple app

* print sizes of other libs; scale to 60k lines

* test the generated app on travis