EngineLayers can hold references to Skia objects and may consume significant
resources.  This change will result in more aggressive cleanup of EngineLayers
by the Dart GC.

See https://github.com/flutter/flutter/issues/31303

Skia allows drawing unpremul images, but filtering them can look bad.
Internally Skia performs this transformation when creating SkImages from
encoded data (so this already happens for MakeCrossContextFromEncoded),
and for consistency/quality it should be done here, too.

Fixes #28785

https://skia.googlesource.com/skia.git/%2Blog/7ecad8791ff1..9adc82c73df0

git log 7ecad8791ff10646d05b74393f1e026e3f6aad7c..9adc82c73df0ef25b708cae8aa48ef9c39ed4c67 --date=short --no-merges --format=%ad %ae %s
2019-04-23 reed@google.com Fixes for saveBehind/drawBehind
2019-04-23 robertphillips@google.com Implement alternate method for determining recycle-ability of allocated GrSurfaces
2019-04-23 mtklein@google.com rename gamma stage gamma_
2019-04-23 robertphillips@google.com Remove the option of disabling explicit resource allocation

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 (mtklein@google.com), and stop
the roller if necessary.

https://skia.googlesource.com/skia.git/%2Blog/f153e221140a..7ecad8791ff1

git log f153e221140adb32b91cbbc45e1f05d08f4fee0c..7ecad8791ff10646d05b74393f1e026e3f6aad7c --date=short --no-merges --format=%ad %ae %s
2019-04-23 mtklein@google.com add third_party/skcms to includes

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 (mtklein@google.com), and stop
the roller if necessary.

https://skia.googlesource.com/skia.git/%2Blog/977b16d9c978..f153e221140a

git log 977b16d9c978f85007613cd0ed05eef6ad0e169e..f153e221140adb32b91cbbc45e1f05d08f4fee0c --date=short --no-merges --format=%ad %ae %s
2019-04-23 skia-recreate-skps@skia-swarming-bots.iam.gserviceaccount.com Update go_deps asset
2019-04-23 skia-autoroll@skia-public.iam.gserviceaccount.com Roll third_party/externals/angle2 c467f7b54188..cff6f150eae1 (1 commits)
2019-04-23 skia-autoroll@skia-public.iam.gserviceaccount.com Roll ../src 3ed0f75776bb..29e17ed23dea (265 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 (mtklein@google.com), and stop
the roller if necessary.

https://skia.googlesource.com/skia.git/%2Blog/731ba99a8581..977b16d9c978

git log 731ba99a8581cb81978e8217d210309880558b09..977b16d9c978f85007613cd0ed05eef6ad0e169e --date=short --no-merges --format=%ad %ae %s
2019-04-23 skia-autoroll@skia-public.iam.gserviceaccount.com Roll third_party/externals/swiftshader bcc71a322953..707ed9974cb3 (3 commits)
2019-04-22 brianosman@google.com Add skcms directory to public includes
2019-04-22 egdaniel@google.com Add wait function on GrContext to wait on semaphores.
2019-04-22 jvanverth@google.com More buffer changes for Metal.
2019-04-21 reed@google.com hide internals of SkColorMatrix (so we can migrate to col-major)

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 (mtklein@google.com), and stop
the roller if necessary.

1f1592edce Add manifest checks for touchscreen feature
630058286f [build] Fix deps for dart_io.
5ee20c99ac [vm/aot/tfa] Workaround for crash in getStaticType
2c304d997f [dartdevc] fix #36372, make JS Array constructor property usable from JS
ef9c25c08b Support codeOffset/Length for CompilationUnit and other nodes.
80bed430c8 Extract AnalysisDriver tests that work with summary1 into a separate test class.
39662f8108 Set ElementAnnotation for directives.
c7279d347b Always lazy create TypeParameterTypeImpl.
27b64953d5 Fixes for applying resolution for fields metadata.
385406ac92 Give LinkedElementFactory its AnalysisSession, fixes for nameOffset.
8b6d04b2ee sort tests
c89e71cd40 The default return type for []= is void.
971f4845d7 [build] Remove last platform -> vm and bin -> vm dependencies. Fix some ODR violations.
3aef424c9c Always add imported / exported files, even if they are parts.
e7a54a9759 Support for TokenType.GT_GT_GT
ec79fc2ff4 update AstBuilder to process "late" modifier
390ba6925d Allow nnbd to be enabled in tests
d1b675055c Read all GenericFunctionType(s) and TypeParameter(s) is lazy AST before reading eager AST.
17db9f986a Simplify type tests in nullable_type_ambiguous_test.dart
dfa56c7031 [vm, interpreter] Invoke field as a bytecode.
2d6313c9e4 Prepare to publish analyzer version 0.36.1
4a33d33297 Store FeatureSet in CompilationUnit.
08832508ec Forward "late" modifier to parser listeners
449cdecda2 [vm/interpreter] Fix bytecode instruction formats in interpreter
6d9d95d938 Add GenericFunctionTypeImpl.declaredElement
fd48001ace Put NNBD modifiers behind a flag
a9b1d9e33b Splice resolved API nodes and unresolved function bodies.
38eed58f61 Fix hints in nullability migration code
d50232a3f5 Plumb new FeatureSet class into AstBuilder.
780f1b6c3e Remove unused imports
c3f822eae6 Attempt to fix failures on the windows bot
47a8ff60e1 Convert more analyzer unit tests
76f177a492 Use a non-null index for all features, even expired ones.
f5224b53e4 [dart_internal] Bump SDK constraint upper-bound to <2.4.0
3d1ca4ae39 Revert "[vm, interpreter] Invoke field as a bytecode."
c85631330d [vm, interpreter] Invoke field as a bytecode.
680744d169 Fix version number strings to always include a patch number.
cb4db33010 [vm/debugger] fix order of type arguments in debugger
1ecedb2341 Fix JsLinkedHashMap memory leak
af0fa108da Add support for required named parameters
a2e06eafff allow built-in keywords as identifier in for-in loop
63658b113c Proposed new API for tracking feature opt in/out
8924c18003 [vm/tests] Revert changes in pkg/vm unit tests after constant-update-2018 was disabled
aaa829695f Fix typo in CHANGELOG.md
78340fdf82 [vm] Support ListInterfaces for android
9e87c16677 Record TopLevelInferenceErrorKind.dependencyCycle in summary2.
3ae2ef7763 parse "late" modifier
b352b5ffb7 [vm, jit] The hottest Smi ops are + < == not + - ==.
3f477a6218 Consolidated CHANGELOG entry for 2.3.0.

Also throw if SkVertices::Builder reports an invalid configuration.

Fixes https://github.com/flutter/flutter/issues/31270

* Revert "fix toString (#8688)"

This reverts commit 9fa73367.

* Revert "Make Rect and RRect use 64 bit doubles, and make them const-able (#8565)"

This reverts commit c1231527.

This reverts commit 4ead9c8f.

Reland tracked in https://github.com/flutter/flutter/issues/31433.

* Make Rect and RRect 64bit and const-able

https://skia.googlesource.com/skia.git/%2Blog/a76fad2d494a..731ba99a8581

git log a76fad2d494af8bde8c3fb34a2de2b359beebab1..731ba99a8581cb81978e8217d210309880558b09 --date=short --no-merges --format=%ad %ae %s
2019-04-22 mtklein@google.com deshard NP and N7 CPU test bots
2019-04-22 mtklein@google.com Revert "simplify and centralize SK_API"
2019-04-22 robertphillips@google.com Add explicit GrSurfaceProxy flag to skip explicit resource allocation (take 2)
2019-04-22 mtklein@google.com remove duplicate SkBase64.h
2019-04-22 mtklein@google.com rm src/compute
2019-04-22 borenet@google.com [docs] Update documentation for branching process
2019-04-11 mtklein@google.com simplify and centralize SK_API
2019-04-22 egdaniel@google.com Fully add back old GrContext flush api.
2019-04-15 mtklein@google.com add constexpr constructor to SkMatrix
2019-04-22 egdaniel@google.com Update comment on vulkan allocator.
2019-04-22 egdaniel@google.com Add back deprecated GrCotnext flush API till clients get fixed.
2019-04-19 brianosman@google.com Add SkSL viewing/editing to viewer
2019-04-22 mtklein@google.com Revert "Add explicit GrSurfaceProxy flag to skip explicit resource allocation"
2019-04-22 skia-recreate-skps@skia-swarming-bots.iam.gserviceaccount.com Update go_deps asset
2019-04-22 skia-autoroll@skia-public.iam.gserviceaccount.com Roll third_party/externals/angle2 145ec7fa7c81..c467f7b54188 (4 commits)
2019-04-22 skia-autoroll@skia-public.iam.gserviceaccount.com Roll third_party/externals/swiftshader a16238df3f28..bcc71a322953 (7 commits)
2019-04-22 skia-autoroll@skia-public.iam.gserviceaccount.com Roll ../src a55917cb9824..3ed0f75776bb (344 commits)
2019-04-21 reed@google.com use portable typeface for new gm
2019-04-21 skia-recreate-skps@skia-swarming-bots.iam.gserviceaccount.com Update SKP version
2019-04-21 rmistry@google.com Skip __init__.py in webpages_playback.py

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

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the roller if necessary.

Relands #8638

This reverts commit bd8c5b13.

Reverts flutter/engine#8656

Reason:  https://github.com/flutter/engine/pull/8656 seems to break the framework windows tests and the engine roll (see https://cirrus-ci.com/task/4704667236827136 and https://github.com/flutter/flutter/pull/31330). The failure has been consistent for 7 consecutive engine-to-framework auto-rolls.

TBR: @chinmaygarde 

This reverts commit 6e79dcd0.

Reverts flutter/engine#8638

Reason: flutter/engine#8638 breaks the post-submit Cirrus tests. See https://cirrus-ci.com/build/5143341531398144 and subsequent post-submit failures. Specifically, ParagraphTest.RightAlignParagraph is failing.

TBR: @GaryQian 

With this, no Skia or Dart roll (or any other engine commit) would accidentally break the framework.

For commits that require manual engine-to-framework rolls, the `build_and_test_host` test would fail. In such cases, the author should explicitly mention **"merge on red as the failure is expected; the engine will be manually rolled into the framework"**.

https://skia.googlesource.com/skia.git/%2Blog/1c0b05afdef8..a76fad2d494a

git log 1c0b05afdef8c0366926d3a5cdbe828ff122cfe2..a76fad2d494af8bde8c3fb34a2de2b359beebab1 --date=short --no-merges --format=%ad %ae %s
2019-04-21 skia-recreate-skps@skia-swarming-bots.iam.gserviceaccount.com Update go_deps asset
2019-04-20 skia-recreate-skps@skia-swarming-bots.iam.gserviceaccount.com Update go_deps asset
2019-04-18 jvanverth@google.com Add Metal support for dynamic buffers.
2019-04-19 reed@google.com Add secret draw-behind method

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 (mtklein@google.com), and stop
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The callbacks can be wired in via the Settings object. Both runtime and shell unit-tests have been patched to test this.

Fixes https://github.com/flutter/flutter/issues/31292.

If the mapping callback is not set or it the callback returns invalid data, ICU initialization will be embedder responsibility.

This affects all embedders and the following have been audited:
* Android: Via a symbol mapping.
* iOS: Via a file mapping.
* Embedder: Via a file mapping.
* Fuchsia: Via a VMO mapping
* Test shells and Flutter tester: Via file mapping with ICU data needing to be next to the executable.

https://skia.googlesource.com/skia.git/%2Blog/cc5d3e09e394..1c0b05afdef8

git log cc5d3e09e39410841ba6e8866680257a92ee5205..1c0b05afdef8c0366926d3a5cdbe828ff122cfe2 --date=short --no-merges --format=%ad %ae %s
2019-04-19 bsalomon@google.com SkClipStack::isRRect succeeds if stack is  an intersection of rects.
2019-04-17 csmartdalton@google.com ccpr: Calculate edge coverage in the coverage processor
2019-04-19 ethannicholas@google.com Fixed internal skslc error with negated literal vectors
2019-04-19 egdaniel@google.com Adjust vulkan memory allocation block size knobs to better match the type of draws we do.
2019-04-17 ethannicholas@google.com reworked SPIR-V binary operations and added support for VectorTimesScalar
2019-04-19 robertphillips@google.com Add explicit GrSurfaceProxy flag to skip explicit resource allocation
2019-04-19 halcanary@google.com SkQP: new docker test code
2019-04-19 ethannicholas@google.com fixed Metal code generation for recursive functions
2019-04-19 michaelludwig@google.com Don't batch across domain modes in GrTextureOp
2019-04-19 brianosman@google.com Convexity checker: Wait for significant x-product when walking edges
2019-04-19 michaelludwig@google.com Update compositing benchmark to use image-set API
2019-04-18 csmartdalton@google.com ccpr: Indicate path fill type by winding direction of cover triangles
2019-04-19 ethannicholas@google.com added error detection for writing to a constant swizzle mask
2019-04-19 kjlubick@google.com [spec] Initial commit for web spec

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 (herb@google.com), and stop
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The GetMapping calls removed in this patch had the same code and had to be repeated across different test harnesses as well as in dart_snapshot.cc. Just make this a factory method so the code is less verbose.

380d0ed Build host Dart binary with -march=core2 on Mac OS X. (#235)

https://skia.googlesource.com/skia.git/%2Blog/e5763787f920..cc5d3e09e394

git log e5763787f920c0c3a30527a596a6c207eb1b220b..cc5d3e09e39410841ba6e8866680257a92ee5205 --date=short --no-merges --format=%ad %ae %s
2019-04-19 ethannicholas@google.com Revert "Revert "added more SPIR-V RelaxedPrecision decorations""
2019-04-19 reed@google.com use char-to-glyph cache in freetype typeface
2019-04-19 brianosman@google.com Remove SK_TREAT_COLINEAR_DIAGONAL_POINTS_AS_CONCAVE

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

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As long as the Mac SDK is i386 ready, engine developers should be able to use the latest version of Xcode to build all artifacts. This issue goes away when gen_snapshot migrates to x64.

https://skia.googlesource.com/skia.git/%2Blog/e8a33ec6d084..e5763787f920

git log e8a33ec6d084fef3200eb8732b453734f4b391ca..e5763787f920c0c3a30527a596a6c207eb1b220b --date=short --no-merges --format=%ad %ae %s
2019-04-17 robertphillips@google.com Allow GrShadowRRectOp::Make to fail

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If the roll is causing failures, please contact the current sheriff (herb@google.com), and stop
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https://skia.googlesource.com/skia.git/%2Blog/8cdae55bf1ac..e8a33ec6d084

git log 8cdae55bf1ac0270b8f7c92f131ec9a18957e84d..e8a33ec6d084fef3200eb8732b453734f4b391ca --date=short --no-merges --format=%ad %ae %s
2019-04-19 skia-recreate-skps@skia-swarming-bots.iam.gserviceaccount.com Update go_deps asset
2019-04-19 skia-autoroll@skia-public.iam.gserviceaccount.com Roll third_party/externals/angle2 82bcffa78747..145ec7fa7c81 (10 commits)
2019-04-19 skia-autoroll@skia-public.iam.gserviceaccount.com Roll third_party/externals/swiftshader abaecd5f2ba7..a16238df3f28 (12 commits)

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 (herb@google.com), and stop
the roller if necessary.

https://skia.googlesource.com/skia.git/%2Blog/9b67802a4cd0..8cdae55bf1ac

git log 9b67802a4cd01fbbe5fcbe9f4117ff68e7b8e751..8cdae55bf1ac0270b8f7c92f131ec9a18957e84d --date=short --no-merges --format=%ad %ae %s
2019-04-19 skia-autoroll@skia-public.iam.gserviceaccount.com Roll ../src f968f64cdf27..a55917cb9824 (433 commits)

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This reverts commit 0fcfa0df.
Windows depends on referencing the snapshot symbols directly instead of
via dlsym. Something in the way these symbolsa are generated in
bin_to_assembly.py is causing them to be inaccessible at runtime.

This was used in some embedder implementations. But that was a while ago.

This reverts commit 905ddb6c.