Should have https://github.com/flutter/flutter/issues/30586 fixed once the engine rolls.

https://skia.googlesource.com/skia.git/%2Blog/c9eeab3d85b9..e25b4472cdd9

git log c9eeab3d85b9c85e49a4d8228ba7468072e2bb0d..e25b4472cdd9f09cd393c9c34651218507c9847b --date=short --no-merges --format=%ad %ae %s
2019-04-02 reed@google.com Move SkTileModes to top level

The AutoRoll server is located here: https://autoroll.skia.org/r/skia-flutter-autoroll

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

If the roll is causing failures, please contact the current sheriff (jlavrova@google.com), and stop
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https://skia.googlesource.com/skia.git/%2Blog/71c0e9422038..c9eeab3d85b9

git log 71c0e94220380f4cbb3a8ba462ef9036fa7ab1ff..c9eeab3d85b9c85e49a4d8228ba7468072e2bb0d --date=short --no-merges --format=%ad %ae %s
2019-04-02 bungeman@google.com Remove Skia version number.
2019-04-02 mtklein@google.com update some FM flags
2019-04-02 michaelludwig@google.com Do not lose existing paint shaders when drawing alpha images
2019-04-02 recipe-mega-autoroller@chops-service-accounts.iam.gserviceaccount.com Roll recipe dependencies (trivial).

The AutoRoll server is located here: https://autoroll.skia.org/r/skia-flutter-autoroll

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

If the roll is causing failures, please contact the current sheriff (jlavrova@google.com), and stop
the roller if necessary.

Sends scroll events from GLFW to the Flutter engine, allowing scrolling
of Scrollables via a scroll wheel.

f6768b6fb3 Update the data version to prevent the use of outdated cached data
8fee2596e5 Remove some unused front_end dependencies
725c070632 report error on type reference before factory keyword
ff99692175 dartfix update analysis options to enable NNBD
aed696cea7 [infra] Update checked in SDKs to 2.2.1-dev.3.0

* Pass environment defines to the compiler

* Remove non-strong platform target

https://skia.googlesource.com/skia.git/%2Blog/f2d9b865d736..71c0e9422038

git log f2d9b865d73631d0052a323558b3c083f7e05188..71c0e94220380f4cbb3a8ba462ef9036fa7ab1ff --date=short --no-merges --format=%ad %ae %s
2019-04-02 mtklein@google.com We don't actually use thesee extensions with GLES
2019-04-02 bsalomon@google.com Revert "Inset blur domain a tiny bit to prevent certain GPUs from sampling transparent black from scratch textures."
2019-04-02 mtklein@google.com add skottie support to fm
2019-04-02 mtklein@google.com allow skipped source/backend pairs in fm
2019-04-02 jvanverth@google.com Fix some more Metal and iOS leaks
2019-04-02 brianosman@google.com Initialize renderability in GrMockOptions
2019-03-29 egdaniel@google.com Remove read access flags from src of memory barriers.
2019-04-02 robertphillips@google.com Add tracking of work to GrVkCommandBuffer
2019-04-02 brianosman@google.com Remove samples that aren't built
2019-04-02 mtklein@google.com allow GMs to fail in DM
2019-04-02 brianosman@google.com Remove redundant setup code in readSurfacePixels
2019-04-02 jvanverth@google.com Updates to iOS build
2019-04-01 herb@google.com Refactor main GPU glyph decisions

The AutoRoll server is located here: https://autoroll.skia.org/r/skia-flutter-autoroll

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If the roll is causing failures, please contact the current sheriff (jlavrova@google.com), and stop
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14fd3b7d6a Report errors on invalid constants in == and !=
4a1b153fe1 [cfe] Enable type promotion in if-elements of literal collections
45bd79c119 [cfe] Fix inference on variable declarations in for-elements
71a3649a5a [cfe] Assume invocations are dead if they aren't reached by type inference
d320f42542 [CFE] Remove redundant null checks in constant evaluator.
405bd06725 [VM] Refactors metrics variables to avoid multiple instances per compiled unit.
3a93cf9464 Update dart_style to 1.2.5.
8ce2d7a4e1 [CFE] Better error messages on errors with user definable operators
c71888d537 [cfe] Async translation of block expressions
28e658814f [dartdevc] Implementing collection concatenation
057497e57b Revert "[vm/runtime] Create separate background compilation queues for optimized and unoptimized compilations."
ba473d579f Unskip co19_2/Control-flow-collections for dart2js.
bcb6df13b9 [vm/runtime] Create separate background compilation queues for optimized and unoptimized compilations.
bfb99d146d [dartdevc] Adding superclass constraints to mixin init
c26f1c6bf7 Do not assume stack trace is not null
9325a3122c [infra] Add missing out directories to the "vm-kernel" fileset.
c2f014064e [vm/debugger] Ensure TopLevel class is finalized when setting breakpoint
e979895efb Revert "[vm] Repair the resolver abstraction."
dd7a6320e3 Rework the way Dartdoc template information is gathered
bb0dc80550 [gardening] Rename flutter engine patch to catch up with roll
010f3e91fa [gardening] Follow-up to temp disable flutter engine gl build
0d0857ca98 [gardening] Temporarily disable flutter engine gl build to unbreak hhh buildbot
0fdaec1b8e [ Service ] Removed extra print statement in test

https://skia.googlesource.com/skia.git/%2Blog/70d8f4f3acbb..f2d9b865d736

git log 70d8f4f3acbbbc6fbce0e1f1753ba475f2c52dac..f2d9b865d73631d0052a323558b3c083f7e05188 --date=short --no-merges --format=%ad %ae %s
2019-03-28 mtklein@google.com Add basic fm_bot script
2019-04-02 brianosman@google.com Remove SkScalarSinCos
2019-04-02 bsalomon@google.com Make GrVkGpuCommandBuffer::CopyInfo hold source as pending read.
2019-04-02 reed@google.com add mtklein to api approvals
2019-04-01 mtklein@google.com remove SkColorFilter::onMakeComposed()
2019-04-02 reed@google.com remove double compose: lerp and mode
2019-04-01 bungeman@google.com Clean up shaper handler.
2019-04-02 fmalita@chromium.org [skottie] Initial gradient ramp effect support
2019-04-01 mvujovic@adobe.com Inset blur domain a tiny bit to prevent certain GPUs from sampling transparent black from scratch textures.
2019-04-02 brianosman@google.com Revert "Remove the NullGL interface (and associated test context)"
2019-04-01 reed@google.com remove asComponentTable introspection method

The AutoRoll server is located here: https://autoroll.skia.org/r/skia-flutter-autoroll

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If the roll is causing failures, please contact the current sheriff (jlavrova@google.com), and stop
the roller if necessary.

This reverts commit c9916474.

https://skia.googlesource.com/skia.git/%2Blog/d962070feb84..70d8f4f3acbb

git log d962070feb84a95e25d99f0a6ad26fd59d32e60b..70d8f4f3acbbbc6fbce0e1f1753ba475f2c52dac --date=short --no-merges --format=%ad %ae %s
2019-04-01 scroggo@google.com SkWuffsCodec: Use drawing to do color correction and scaling

The AutoRoll server is located here: https://autoroll.skia.org/r/skia-flutter-autoroll

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https://skia.googlesource.com/skia.git/%2Blog/1acf79a3e5b8..d962070feb84

git log 1acf79a3e5b8abfca56193e4643b51f3c552389c..d962070feb84a95e25d99f0a6ad26fd59d32e60b --date=short --no-merges --format=%ad %ae %s
2019-04-01 recipe-mega-autoroller@chops-service-accounts.iam.gserviceaccount.com Roll recipe dependencies (trivial).
2019-04-02 skia-recreate-skps@skia-swarming-bots.iam.gserviceaccount.com Update go_deps asset
2019-04-02 skia-autoroll@skia-public.iam.gserviceaccount.com Roll third_party/externals/angle2 3115a0fc17fa..6cb0cff57376 (9 commits)
2019-04-02 skia-autoroll@skia-public.iam.gserviceaccount.com Roll ../src e01c3e081ff3..b3f3a36219a1 (475 commits)

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https://skia.googlesource.com/skia.git/%2Blog/3f6a2ac63670..1acf79a3e5b8

git log 3f6a2ac636700b5bb27834938de3b43f71a33beb..1acf79a3e5b8abfca56193e4643b51f3c552389c --date=short --no-merges --format=%ad %ae %s
2019-04-02 skia-autoroll@skia-public.iam.gserviceaccount.com Roll third_party/externals/swiftshader 52a67b6495ce..459453a96257 (5 commits)

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* Add null check in FontWeight.lerp

* Add Unit tests for FontWeight.lerp

https://skia.googlesource.com/skia.git/%2Blog/b27667a15a15..3f6a2ac63670

git log b27667a15a15ce31d135538a409c419c0b8b0d1b..3f6a2ac636700b5bb27834938de3b43f71a33beb --date=short --no-merges --format=%ad %ae %s
2019-04-01 reed@google.com remove unneeded asACompose

The AutoRoll server is located here: https://autoroll.skia.org/r/skia-flutter-autoroll

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Remove platform views inside OnDispose might cause issue if it happens before SubmitFrame and the active_composition_order has not been updated.
We will be left at a situation where the active_composition_order still contains the old view, but the view is actually removed from the UIView hierarchy.

We now cache the views need to be removed in OnDispose and actually remove them in SubmitFrame. At the same time, we remove stop detaching the subviews if they were disposed. 

As a side effect, this update will also fix flutter/flutter#30220

When attempting to shutdown and subsequently restart the VM, having the
VM own this data introduces lifecycle issues due to circular references.

https://skia.googlesource.com/skia.git/%2Blog/de206c75c2c8..b27667a15a15

git log de206c75c2c802f6f1e4ccb8a6b8a00765e9f085..b27667a15a15ce31d135538a409c419c0b8b0d1b --date=short --no-merges --format=%ad %ae %s
2019-04-01 brianosman@google.com Remove ToolUtils::write_pixels
2019-04-01 nifong@google.com Include wasm debugger in continuous build part 2
2019-03-27 bungeman@google.com Expose basic shaper iterators.
2019-04-01 reed@google.com mark introspection methods as deprecated
2019-04-01 michaelludwig@google.com Add geometry domain for non-rectilinear quads
2019-04-01 csmartdalton@google.com Fix mkdir_p in skpbench
2019-04-01 nifong@google.com Include wasm debugger in continuous build
2019-04-01 fmalita@chromium.org [sksg] Refactor gradient implementation
2019-03-28 bungeman@google.com Cache data stream for CG typefaces.
2019-04-01 bsalomon@google.com GrBackendTextureImageGenerator proxy callback uses unique key to find existing GrTexture.
2019-04-01 robertphillips@google.com Make prepareSurfaceForExternalIO always flush
2019-04-01 bsalomon@google.com Make GrVkGpuRTCommandBuffer::CommandBufferInfo hold textures by pending read.
2019-04-01 rmistry@google.com Remove 4 page sets that are not useful as SKPs
2019-04-01 bsalomon@google.com Make lazy proxies have 2 modes for proxy/surface key management.

The AutoRoll server is located here: https://autoroll.skia.org/r/skia-flutter-autoroll

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75b2f9f919 Move more HintCode tests to individual files:
acb62b97fe Add a default URL for lints
3fd124db1f [vm] Repair the resolver abstraction.
e979448597 Patch expectations for tests where AST linking does better / differently.
1e77c187c8 Update front-end status for added tests and changed results
87de68341f [CFE] Disallow property access on instance constants.
4ae5b272cb [vm/bytecode/compiler] Fix dropping of expression stack values when generating Throw
1a3e8dda3b Handle nested unevaluated constants in constant evaluator
277f65ec93 [CFE] Permit evaluating a const variable more than once.
a88b653e03 [CFE] Bubble out InvalidExpression from unevaluated constants.
05dd851566 Test late CFE constant evaluation.
413315cacd Add some tests for constants.
dc1f6b352a Update front-end status for co19 roll
154c324786 [vm/ffi] Lock out structs on 32-bit platforms.
79bb83a927 [infra] Fix debianpackage build
a062221b76 [vm] Re-number class ids for internal/external typed data and typed data views
c14a15bad1 Remove third_party/google_test from index
66f16d3d5e Resynthesize import/export combinators.
4e3d1400d5 Resynthesize ImportElement.isDeferred from AST.
8a5901a7af Support for isCovariant in fields.
9113bb5855 Issue 36380. Increment DATA_VERSION.
e6b0676f58 Change comment style in a few more files
94362f1af0 [vm] Unify internal/external/view typed data into new RawTypedDataBase class
c7dd9c1c23 Perform top-level inference using elements.
cd34ec901c [gardening] Flutter patch is no longer needed.
3642eddca1 Create an experiment flag for triple-shift and move existing support for the operator behind the new flag

* Make resource context primary on iOS

https://skia.googlesource.com/skia.git/%2Blog/73cc4e8d5fcf..de206c75c2c8

git log 73cc4e8d5fcfdad5a09bf324bb21479a16e8e54e..de206c75c2c802f6f1e4ccb8a6b8a00765e9f085 --date=short --no-merges --format=%ad %ae %s
2019-03-27 brianosman@google.com Remove the NullGL interface (and associated test context)
2019-03-29 mtklein@google.com more opinionated file loading in fm

The AutoRoll server is located here: https://autoroll.skia.org/r/skia-flutter-autoroll

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

If the roll is causing failures, please contact the current sheriff (jlavrova@google.com), and stop
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https://skia.googlesource.com/skia.git/%2Blog/bb482ab871a2..73cc4e8d5fcf

git log bb482ab871a29fad004f318210e0e01d44110a37..73cc4e8d5fcfdad5a09bf324bb21479a16e8e54e --date=short --no-merges --format=%ad %ae %s
2019-04-01 robertphillips@google.com Temporarily restore old behavior of read/writeSurfacePixels

The AutoRoll server is located here: https://autoroll.skia.org/r/skia-flutter-autoroll

Documentation for the AutoRoller is here:
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If the roll is causing failures, please contact the current sheriff (jlavrova@google.com), and stop
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https://skia.googlesource.com/skia.git/%2Blog/5ee611b26f23..bb482ab871a2

git log 5ee611b26f23cda16972209a56ccc38d964f6a20..bb482ab871a29fad004f318210e0e01d44110a37 --date=short --no-merges --format=%ad %ae %s
2019-04-01 skia-recreate-skps@skia-swarming-bots.iam.gserviceaccount.com Update go_deps asset
2019-04-01 skia-autoroll@skia-public.iam.gserviceaccount.com Roll third_party/externals/angle2 6446c8882fa3..3115a0fc17fa (2 commits)
2019-04-01 skia-autoroll@skia-public.iam.gserviceaccount.com Roll ../src 871828938944..e01c3e081ff3 (525 commits)
2019-04-01 skia-autoroll@skia-public.iam.gserviceaccount.com Roll third_party/externals/swiftshader 5bb034db6243..52a67b6495ce (9 commits)

The AutoRoll server is located here: https://autoroll.skia.org/r/skia-flutter-autoroll

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

If the roll is causing failures, please contact the current sheriff (jlavrova@google.com), and stop
the roller if necessary.

https://skia.googlesource.com/skia.git/%2Blog/acb4829c1be4..5ee611b26f23

git log acb4829c1be4bd6be53ea750effd94c07da95632..5ee611b26f23cda16972209a56ccc38d964f6a20 --date=short --no-merges --format=%ad %ae %s
2019-03-31 reed@google.com Add sample to show strokeandfill and better alternatives

The AutoRoll server is located here: https://autoroll.skia.org/r/skia-flutter-autoroll

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If the roll is causing failures, please contact the current sheriff (jlavrova@google.com), and stop
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https://skia.googlesource.com/skia.git/%2Blog/83edfbe736fd..acb4829c1be4

git log 83edfbe736fdaad67ad8ca6c88227b0e6c8df853..acb4829c1be4bd6be53ea750effd94c07da95632 --date=short --no-merges --format=%ad %ae %s
2019-03-31 skia-recreate-skps@skia-swarming-bots.iam.gserviceaccount.com Update SKP version

The AutoRoll server is located here: https://autoroll.skia.org/r/skia-flutter-autoroll

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If the roll is causing failures, please contact the current sheriff (jlavrova@google.com), and stop
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https://skia.googlesource.com/skia.git/%2Blog/2fdbeae32785..83edfbe736fd

git log 2fdbeae3278592857f02a7eb2f5199f419dfa28e..83edfbe736fdaad67ad8ca6c88227b0e6c8df853 --date=short --no-merges --format=%ad %ae %s
2019-03-31 skia-recreate-skps@skia-swarming-bots.iam.gserviceaccount.com Update go_deps asset

The AutoRoll server is located here: https://autoroll.skia.org/r/skia-flutter-autoroll

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If the roll is causing failures, please contact the current sheriff (jlavrova@google.com), and stop
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https://skia.googlesource.com/skia.git/%2Blog/a6dd1ebd42cf..2fdbeae32785

git log a6dd1ebd42cf647b34e002ddf4f676b96ceda708..2fdbeae3278592857f02a7eb2f5199f419dfa28e --date=short --no-merges --format=%ad %ae %s
2019-03-30 reed@google.com Start to unify signatures: return bool

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https://skia.googlesource.com/skia.git/%2Blog/c9822a1818ba..a6dd1ebd42cf

git log c9822a1818ba8fe91dbea28e592fd18034899e3e..a6dd1ebd42cf647b34e002ddf4f676b96ceda708 --date=short --no-merges --format=%ad %ae %s
2019-03-30 reed@google.com Revert "Reland "GPU support for SkMixers""

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https://skia.googlesource.com/skia.git/%2Blog/265fd3de3527..c9822a1818ba

git log 265fd3de352790725f6c87cce3e5f3dd396e20e7..c9822a1818ba8fe91dbea28e592fd18034899e3e --date=short --no-merges --format=%ad %ae %s
2019-03-30 reed@google.com Reland "GPU support for SkMixers"

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https://skia.googlesource.com/skia.git/%2Blog/59b733715141..265fd3de3527

git log 59b733715141b732ce3fb73b8870851f616c3163..265fd3de352790725f6c87cce3e5f3dd396e20e7 --date=short --no-merges --format=%ad %ae %s
2019-03-30 skia-recreate-skps@skia-swarming-bots.iam.gserviceaccount.com Update go_deps asset

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1e82544b07 [gardening] Attempt to paper over failing flutter test affected by https://dart-review.googlesource.com/c/sdk/+/97311.
dfbdf0a187 Support for function typed formal parameters.
e46fa1cf1d Revert "[VM] Ensure Top level class is finalized for loadedscripts in library"
e0a2651ce0 [cfe] Fix downcasts added during set/map disambiguation
f21d521d0e [cfe] Fix pre-inference set/map disambiguation
6b19aa821b [cfe] Do type checks on spreads during inference
1a5ed8247f [fasta] Fix typos and copy-paste errors in a test case
584affcffa [cfe] Add initial support for 'for' and for-in elements in maps
fa7e0c7531 [cfe] Add element type checks in spreads
1b2a4b8eb1 Convert some tests to DriverResolutionTest
fb58826aa3 [CFE] Compensate for lowering and desugaring in spread.
7ef28f0b03 Handle constant field init registration correctly.
da0de0a867 Handle native field impact correctly from ir constants
00d65e2d84 Roll co19 to revision c3b33ee
0560014c79 Remove unused error codes
e8b56268ef Resolve constructor initializers and redirections.
c185945507 [vm/aot] Ensure global object pool is relocated by compactor and reloaded when returning from natives
d23909802e [vm/compiler] Eliminate dead CatchBlockEntry Parameter-s
69790e7eb4 Updated Dart.g, tests & status files to support ui-as-code collections
1bf1ca1933 Revert "Update dart_style to 1.2.5."
4fe2f6f349 Add more tests to the incremental compiler
611a53ee5e Update dart_style to 1.2.5.
b7f69e24a2 dartdevc and bazel worker can use incremental compiler
a506c708f2 [co19] DEPS updated
9b77e4c507 Include constructors into available suggestions.
0eb76a5b5a Move await for of null tests to a different file.
8d699db9af Update spread_collections/inference_test to use Type.== instead of identical
edf470bf83 Initial sketch of dartdoc support
1b643e5c1f Support for mixins.
bc0148cf87 [ddc] Skip unsupported co19 tests on ddc/ddk
15b4e57510 [ VM / Service ] Fixed failing isolate_lifecycle_test
4c50d06ac5 Handle inconsistent analysis exception during a refactoring (issue 36149)
ae62f7fefe [vm, gc] Make incremental write-barrier elimination safe.
d07e33e11f Convert more comments from block to line style
926a6c0958 Convert more comments
dfcc52f909 [vm/dart:io/fuchsia] Improve fdio_pipe_half signature, step 2.
1926f69e4d Include available classes when includeConstructorSuggestions is true.
d0fda82493 Clean up some of the unused task model support in test code
2bc81be75a [infra] Some missing interpreter bot configurations.
ac2c934563 Reland "[ VM / dart:isolate ] Added ability to set names for spawned isolates."
380ae2ce55 [ Observatory ] Fixed links for 'part's in dart:* scripts not being created.

It ensures that every OpacityLayer can be optimized by retained
rendering.

Tested with `flutter test --local-engine=host_debug_unopt` in
flutter/flutter/packages/flutter.

Related issues: #21756 #23535

Courtesy of google's "CommonTypos" analysis.