Fixes https://github.com/flutter/flutter/issues/3352

If two repaint boundaries mark themselves dirty, but the second one is a
child of the first, then the second one will get repainted by the first
and then when we come to paint it directly, we get confused because it
isn't dirty any more.

We ran into this in layout before. Apply the same fix. Also, apply the
same fix to composition while we're at it.

Add a Performance Overlay toggle to the Gallery app

Exception stack variable was shadowing the function argument stack.

We're getting back to the point where we have a bunch of foundation APIs
and it's getting confusing having them mixed with services/.

Make update-packages cover dev/benchmarks.

update-packages only looks one level down, instead of
changing that, I'm just adding dev/benchmarks explicitly.

This will unbreak the bots which are dying trying to
flutter drive dev/benchmarks/complex_layout without
pub get having been run there.

@yjbanov @devoncarew

...even if the test fails.

until we have a fix for the breaking changes

Adding `@optionalTypeArgs`.

With the new dev build we've got the updated linter and so can use the `@optionalTypeArgs` annotation (in `meta 0.12.0`).

Bonus: this lets us clean up one more Regexp in the `analyze` command! :)

Add a basic scrolling test for the Gallery home page.

Repaint child view on attach / detach.

* run pub for analyze and test

* don't run pub when doing repo analysis

* move logic for when to run pub into the commands

* re-write ternary expression

* Improvements to the Grid list demo

* More nits and fixes to grid demo in gallery

Current numbers from my Nexus 5:
  "average_frame_build_time_millis": 22.6854,
  "missed_frame_build_budget_count": 15,
  "frame_count": 15

Filed https://github.com/flutter/flutter/issues/3296

@yjbanov @hansmuller @vlidholt

Bump dart SDK to 1.16.0-dev.5.0.

...by adding tests to our examples that don't import flutter_test, which
pins the relevant dependencies.

Also, provide more information when complaining about leaked transient
callbacks in tests.

Also, make tests display full information when they have an exception,
by bypassing the throttling we have for Android logging in tests.

Also, make the word wrapping not wrap stack traces if they happen to
be included in exception output.

Also, fix a leaked transient callback in the checkbox code.

Among other things, grabs support for `@optionalTypeArgs`.

This is the last dev push for 1.16.  Here on out we're in cherry-pick season until 1.16 final.

Move flutter drive to use 8183 to not conflict with diagnostic server

When @jason-simons added the diagnostic server on Android this
happened to conflict with flutter drive's usage of 8182.

We really should fix both of these port users to be dynamic
but this fixes https://github.com/flutter/flutter/issues/3291
for now.

@yjbanov

* Fix Block intrinsic functions

* Update block_test.dart

Fix the test per travis

This also shrinks the width of the error messages a bit because now that
we use 'package:' URLs the stacks are a bit narrower.

See https://github.com/flutter/flutter/issues/3233

* styles updates for the api docs

* update library docs

* use the new --favion and --use-categories options for dartdoc

Also fill in some related dartdocs.

Now past halfway though material.dart by files.