Simplify FlDartProject by removing the path arguments - we'll assume that it's
in the standard bundle layout and add new methods later if we need to support
other cases.

Copy the nnbd SDK so that the analyzer works and can migrate

Include header file without absolute path if the header file belongs to
the same directory as source file.

* null-annotate remaining engine code

* Roll CanvasKit to 0.16.1

Fixes https://github.com/flutter/flutter/issues/58014
Fixes https://github.com/flutter/flutter/issues/56938

* Use multiple shared color arrays

* Use fresh color arrays for computeTonalColors

* Use drawColorInt

* Add TODO to use a flattened array when CanvasKit supports it

https://skia.googlesource.com/skia.git/+log/59f31b143ccd..288ecf60bde8

2020-06-05 egdaniel@google.com Use main command buffer for updateBackendTexture in vulkan.
2020-06-05 michaelludwig@google.com Detect empty clip when difference op clips everything
2020-06-05 csmartdalton@google.com Handle tessellated paths that require more segments than are supported
2020-06-05 mtklein@google.com tiny fixup: depend on :skx
2020-06-05 mtklein@google.com add structure for normal SKX opts
2020-06-05 senorblanco@chromium.org Dawn: fix for abandoned contexts.
2020-06-05 kjlubick@google.com [canvaskit] Fix infrequent crash in SkFontMgr.FromData
2020-06-05 mtklein@google.com remove sse4.1 opts level
2020-06-05 skia-recreate-skps@skia-swarming-bots.iam.gserviceaccount.com Update Go Deps
2020-06-05 skia-autoroll@skia-public.iam.gserviceaccount.com Roll ANGLE from 989c790d4b8b to b10f4b94aa17 (11 revisions)
2020-06-05 skia-autoroll@skia-public.iam.gserviceaccount.com Roll Chromium from 2f74454086a5 to b7bb5840cba2 (462 revisions)
2020-06-05 skia-autoroll@skia-public.iam.gserviceaccount.com Roll SwiftShader from 0711869b5f20 to e3eb327e8c3c (1 revision)
2020-06-05 skia-autoroll@skia-public.iam.gserviceaccount.com Roll dawn from 783cd5a79c8a to 0a6a9d86926e (1 revision)
2020-06-04 jlavrova@google.com ICU optimization

If this roll has caused a breakage, revert this CL and stop the roller
using the controls here:
https://autoroll.skia.org/r/skia-flutter-autoroll
Please CC tdenniston@google.com on the revert to ensure that a human
is aware of the problem.

To report a problem with the AutoRoller itself, please file a bug:
https://bugs.chromium.org/p/skia/issues/entry?template=Autoroller+Bug

Documentation for the AutoRoller is here:
https://skia.googlesource.com/buildbot/+doc/master/autoroll/README.md

https://dart.googlesource.com/sdk.git/+log/62903873df30..249cb9c974e1

2020-06-05 sra@google.com [benchmark] BigIntParsePrint lint fixes
2020-06-05 bkonyi@google.com [ VM Service / DDS ] Redirect web socket connection requests made to VM Service to DDS
2020-06-05 rmacnak@google.com [vm, gc] Prevent a program with sufficient idle time and dominated by direct old-space allocations from avoiding scavenges for too long.
2020-06-04 scheglov@google.com Implement allowedExperimentsJson for EmbedderSdk.
2020-06-04 rnystrom@google.com Migrate language_2/number to NNBD.
2020-06-04 scheglov@google.com Fix type cast exception in AddExplicitCast.

If this roll has caused a breakage, revert this CL and stop the roller
using the controls here:
https://autoroll.skia.org/r/dart-sdk-flutter-engine
Please CC dart-vm-team@google.com on the revert to ensure that a human
is aware of the problem.

To report a problem with the AutoRoller itself, please file a bug:
https://bugs.chromium.org/p/skia/issues/entry?template=Autoroller+Bug

Documentation for the AutoRoller is here:
https://skia.googlesource.com/buildbot/+doc/master/autoroll/README.md

* add nullability annotations to lib/ui/painting.dart

* add nullability annotations to lib/web_ui painting.dat

* add nullability annotations to ui/text.dart

This is causing rendering artifacts on intel.
Co-authored-by: NDavid Reveman <reveman@google.com>

This stops events and platform messages generating errors when the engine has
failed to initialize.