Adds an emulated mouse cursor for devices that don't typically have a traditional mouse. Enables mouse-like user interactions by using gamepad devices.

flutter/flutter#76092
flutter/flutter#14967

Unit tests blocked by: flutter/flutter#70197 label added

Spotted elsewhere in the file while taking a quick pass over 77a2b31b
before merging.

Send a null response to signal that a message is not implemented on the web text input channel (#25314)

Per https://fuchsia.dev/fuchsia-src/concepts/testing/v1_test_component,
in order to access non-basic system services like Vulkan loader and
sysmem allocator, we need to add "system-services" field to the cmx
metadata file.

Unittests like "shell_test" requires Vulkan to run properly, so we
add Vulkan loader and sysmem services; for Flutter runner tests,
we also need to add fuchsia.ui.scenic.Scenic since the test needs
to create a Scenic session as well.

TEST=shell_tests (SkpWarmupTest.Basic/SkpWarmupTest.Image)
     flutter_runner_tests (EngineTest.SkpWarmUp) on FEMU

https://dart.googlesource.com/sdk.git/+log/fb5d27696aa8..35a7d7f630f4

2021-03-31 dart-luci-ci-builder@dart-ci.iam.gserviceaccount.com Version 2.13.0-186.0.dev
2021-03-31 dart-luci-ci-builder@dart-ci.iam.gserviceaccount.com Version 2.13.0-185.0.dev
2021-03-31 dart-luci-ci-builder@dart-ci.iam.gserviceaccount.com Version 2.13.0-184.0.dev
2021-03-31 dart-luci-ci-builder@dart-ci.iam.gserviceaccount.com Version 2.13.0-183.0.dev
2021-03-31 dart-luci-ci-builder@dart-ci.iam.gserviceaccount.com Version 2.13.0-182.0.dev
2021-03-30 dart-luci-ci-builder@dart-ci.iam.gserviceaccount.com Version 2.13.0-181.0.dev

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

https://skia.googlesource.com/skia.git/+log/428523f9a4dc..8ed7a8d1c659

2021-03-31 csmartdalton@google.com Extract a GrVertexChunkArray class with a builder
2021-03-31 rmistry@google.com Add new motionmark SKPs
2021-03-31 rmistry@google.com Replace desk_intelwiki.skp with desk_gujuratiwiki.skp
2021-03-31 skia-autoroll@skia-public.iam.gserviceaccount.com Roll skcms from b9593d4e39ea to 4e8691e28194 (1 revision)
2021-03-31 johnstiles@google.com Run the inliner on GLES devices only.
2021-03-31 johnstiles@google.com Add support for constant-folded array inequality checks.
2021-03-31 csmartdalton@google.com Use 4x msaa for all dm testing
2021-03-31 johnstiles@google.com Add test for folding of == and != for arrays.
2021-03-31 reed@google.com Add drawPatch to canvaskit
2021-03-31 bsalomon@google.com SkAuto[S]TMalloc only for trivially constructible/destructible.
2021-03-31 skia-recreate-skps@skia-swarming-bots.iam.gserviceaccount.com Update SKP version
2021-03-31 skia-autoroll@skia-public.iam.gserviceaccount.com Roll Chromium from d6926860006d to de65860ffd71 (501 revisions)
2021-03-31 skia-autoroll@skia-public.iam.gserviceaccount.com Roll Dawn from d7d98509da5c to 864a36474205 (28 revisions)
2021-03-31 bsalomon@google.com GrConvertPixels takes pixmaps
2021-03-30 herb@google.com remove unused functions from glyph run classes
2021-03-30 egdaniel@google.com Grab mutex before reseting vk command pools.
2021-03-30 jvanverth@google.com Add compute methods to GrD3DDirectCommandList.
2021-03-30 jlavrova@google.com Handle the case when one grapheme includes more than one run.

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 mtklein@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

This method doesn't mutate the value of the underlying variant.

Fixes https://github.com/flutter/flutter/issues/79472

This change introduces a semantics flag to indicate whether a node
represents a virtual keyboard key.

Start migrating away from hard-coded gtest_filters in femu_test.py

* Reland "Fixes android voice access delete text, redo, and undo actions. (#25050)"

This reverts commit 4c6abc1e.

* fix condition

https://skia.googlesource.com/skia.git/+log/7b41798fd606..589adda93059

2021-03-30 shrekshao@google.com WebGPU API evolution GPUExtent3D.depth -> depthOrArrayLayers

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 mtklein@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/07c67e891edb..4535b2736e4e

2021-03-30 dart-luci-ci-builder@dart-ci.iam.gserviceaccount.com Version 2.13.0-177.0.dev

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

This will cause the previous texture binding used by Skia to be
incorrectly unbound, such that should they need to re-used an existing
binding, we'll end up rendering blank instead.

Instead we should be using

    context->flushAndSubmit();
    context->resetContext(kAll_GrBackendState);

in `EmbedderExternalTextureGL::ResolveTexture` in order to notify Skia
that we've updated handles within the current binding and invalidate any
assumptions about previous modifications it has made to the context.

This reverts commit d6e59460.

Co-authored-by: Aaron Clarke <gaaclarke>