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.

Previously, only the most basic tests were run in AOT mode.

Fixes https://github.com/flutter/flutter/issues/29798

https://skia.googlesource.com/skia.git/%2Blog/73c6c9d26870..59b733715141

git log 73c6c9d268708f75e2fcdea6b2f7b7e2bf6eacae..59b733715141b732ce3fb73b8870851f616c3163 --date=short --no-merges --format=%ad %ae %s
2019-03-29 recipe-mega-autoroller@chops-service-accounts.iam.gserviceaccount.com Roll recipe dependencies (trivial).
2019-03-29 ethannicholas@google.com Revert "GPU support for SkMixers"
2019-03-29 ethannicholas@google.com GPU support for SkMixers

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 (stani@google.com), and stop
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Fixes https://github.com/flutter/flutter/issues/30122

Cleanup repeated rules.

https://skia.googlesource.com/skia.git/%2Blog/7eeb74fdfd84..73c6c9d26870

git log 7eeb74fdfd8453b4fc0f0460ade48d4097444043..73c6c9d268708f75e2fcdea6b2f7b7e2bf6eacae --date=short --no-merges --format=%ad %ae %s
2019-03-29 bsalomon@google.com Move new convex path towards the end of the path array in GM convexpaths.
2019-03-29 michaelludwig@google.com Interpolate coverage in screen space for perspective quads
2019-03-29 csmartdalton@google.com Split GrCCCoverageProcessor into subclasses
2019-03-29 ethannicholas@google.com fix SkSL lexer's handling of invalid characters
2019-03-29 bsalomon@google.com In GrAAConvexPathRenderer check whether middle quadtric control point is close to line segment between first and last control points and if so draw as a line.
2019-03-29 michaelludwig@google.com Add reproduction test case for crbug/947055
2019-03-29 fmalita@chromium.org [skottie] Allow extra-normal Bezier interpolation
2019-03-29 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

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

Enables building of the GLFW shell and the related unit tests.

libtxt: track the start and end x positions of glyph blobs for more accurate rendering of text decorations (#8368)

Fixes https://github.com/flutter/flutter/issues/30041
Fixes https://github.com/flutter/flutter/issues/24337

The font manager returned by SkFontMgr::RefDefault is determined by Skia's
build configuration flags.  Embedders may want to use a default font manager
other than the one selected by their build of Skia.

https://skia.googlesource.com/skia.git/%2Blog/84a53268af92..7eeb74fdfd84

git log 84a53268af92ca5a620c000a6199513350fdde36..7eeb74fdfd8453b4fc0f0460ade48d4097444043 --date=short --no-merges --format=%ad %ae %s
2019-03-29 robertphillips@google.com Add checks that the GrResourceAllocator is operating as expected
2019-03-29 bungeman@google.com Update SkTLazy includes.
2019-03-29 jvanverth@google.com Reland "Reland "Fix blurry edges on large ovals.""

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/a2cec203eea8..84a53268af92

git log a2cec203eea8d866ccd4e3d71f060f36210e3e1b..84a53268af92ca5a620c000a6199513350fdde36 --date=short --no-merges --format=%ad %ae %s
2019-03-29 skia-autoroll@skia-public.iam.gserviceaccount.com Roll third_party/externals/swiftshader 51562f15f4ad..5bb034db6243 (1 commits)

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

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https://skia.googlesource.com/buildbot/+/master/autoroll/README.md

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

https://skia.googlesource.com/skia.git/%2Blog/57b7a792bb6f..a2cec203eea8

git log 57b7a792bb6f098690243be62f851384c6a9a179..a2cec203eea8d866ccd4e3d71f060f36210e3e1b --date=short --no-merges --format=%ad %ae %s
2019-03-28 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 (stani@google.com), and stop
the roller if necessary.

https://skia.googlesource.com/skia.git/%2Blog/bf4229cc10a1..57b7a792bb6f

git log bf4229cc10a10db751284d8d8d067287cfe8b542..57b7a792bb6f098690243be62f851384c6a9a179 --date=short --no-merges --format=%ad %ae %s
2019-03-29 skia-recreate-skps@skia-swarming-bots.iam.gserviceaccount.com Update go_deps asset
2019-03-29 skia-autoroll@skia-public.iam.gserviceaccount.com Roll ../src eb8d3bc0b607..871828938944 (487 commits)
2019-03-29 skia-autoroll@skia-public.iam.gserviceaccount.com Roll third_party/externals/angle2 8116d646b3f8..6446c8882fa3 (3 commits)
2019-03-29 skia-autoroll@skia-public.iam.gserviceaccount.com Roll third_party/externals/swiftshader fc8a46d0af96..51562f15f4ad (1 commits)
2019-03-29 skia-autoroll@skia-public.iam.gserviceaccount.com Roll third_party/externals/swiftshader c9d98716d2e7..fc8a46d0af96 (1 commits)

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

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https://skia.googlesource.com/buildbot/+/master/autoroll/README.md

If the roll is causing failures, please contact the current sheriff (stani@google.com), and stop
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https://skia.googlesource.com/skia.git/%2Blog/01fe26360660..bf4229cc10a1

git log 01fe263606601d5a95272e3bdf086cb2b85e2d74..bf4229cc10a10db751284d8d8d067287cfe8b542 --date=short --no-merges --format=%ad %ae %s
2019-03-28 recipe-mega-autoroller@chops-service-accounts.iam.gserviceaccount.com Roll recipe dependencies (trivial).
2019-03-29 skia-autoroll@skia-public.iam.gserviceaccount.com Roll third_party/externals/swiftshader 37628f09a4c5..c9d98716d2e7 (1 commits)
2019-03-28 recipe-mega-autoroller@chops-service-accounts.iam.gserviceaccount.com Roll recipe dependencies (trivial).
2019-03-28 recipe-mega-autoroller@chops-service-accounts.iam.gserviceaccount.com Roll recipe dependencies (trivial).
2019-03-28 skia-autoroll@skia-public.iam.gserviceaccount.com Roll third_party/externals/swiftshader 48b3587f8ea4..37628f09a4c5 (1 commits)
2019-03-28 fmalita@chromium.org [skottie] Tweak Shaper test tolerances to fix NativeFonts bots

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 (stani@google.com), and stop
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https://skia.googlesource.com/skia.git/%2Blog/cc8c7bee7925..01fe26360660

git log cc8c7bee792573f8e9dc108236d3af7621ad4f49..01fe263606601d5a95272e3bdf086cb2b85e2d74 --date=short --no-merges --format=%ad %ae %s
2019-03-28 fmalita@chromium.org [skottie] Add support for BodyMovin 5.5.0 keyframes
2019-03-28 recipe-mega-autoroller@chops-service-accounts.iam.gserviceaccount.com Roll recipe dependencies (trivial).
2019-03-28 skia-autoroll@skia-public.iam.gserviceaccount.com Roll third_party/externals/swiftshader 4aa9bf12f7e0..48b3587f8ea4 (1 commits)
2019-03-28 stani@google.com Add API to get canvas wrapped by SkPaintFilterCanvas
2019-03-28 skia-autoroll@skia-public.iam.gserviceaccount.com Roll third_party/externals/swiftshader a563dd8c5734..4aa9bf12f7e0 (1 commits)
2019-03-28 recipe-mega-autoroller@chops-service-accounts.iam.gserviceaccount.com Roll recipe dependencies (trivial).
2019-03-28 skia-autoroll@skia-public.iam.gserviceaccount.com Roll third_party/externals/swiftshader 0839cbda698f..a563dd8c5734 (2 commits)
2019-03-28 recipe-mega-autoroller@chops-service-accounts.iam.gserviceaccount.com Roll recipe dependencies (trivial).
2019-03-28 robertphillips@google.com Remove unused PixelOpsFlags values
2019-03-28 skia-autoroll@skia-public.iam.gserviceaccount.com Roll third_party/externals/angle2 e810ad90799c..8116d646b3f8 (6 commits)

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

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update buildroot dep for https://github.com/flutter/buildroot/commit/e2ca4571fa39be20ab1bf67c65d4700612756af2 (#8359)

Previously the engine was creating multiple `ShapeNode`s all underneath
the same root `EntityNode` at local space z=0. This caused frequent
z-fighting within Flutter layers.

This patch updates the engine to only create one ShapeNode per
EntityNode, which fixes the z-fighting independent of layer elevation.
Z-fighting is still possible from actually setting multiple layers to
the same z in world space using Flutter elevation.

flutter/flutter#25226

f29e100f42 [dart/fuzzer] Generate DartFuzz API tables automatically
f0027dfea3 [CFE] JS number semantics for constant subtype checks.
018fd36557 [CFE] Handle spread and if in const map literals.
b5be157e09 [CFE] Handle spread and if in const set literals.
0b57b67ecb [CFE] Move const set desugaring to constant evaluator.
102b1fa39e [CFE] Handle spread and if in const list literals.
8611cbf7df [CFE] Add constant update flag to collection tests.
665d2d0003 [CFE] Leave const collections to the constant evaluator.

https://skia.googlesource.com/skia.git/%2Blog/05be23dbd3c4..cc8c7bee7925

git log 05be23dbd3c4565cb23744c154df80b0ebc0208a..cc8c7bee792573f8e9dc108236d3af7621ad4f49 --date=short --no-merges --format=%ad %ae %s
2019-03-28 reed@google.com add bench for colorfilter-mixer
2019-03-28 fmalita@chromium.org [skottie] Compute tight bounds in skottie::Shaper
2019-03-21 martin@mainframe.co.uk fix metal build errors with preprocessor definitions
2019-03-28 recipe-mega-autoroller@chops-service-accounts.iam.gserviceaccount.com Roll recipe dependencies (trivial).
2019-03-28 nifong@google.com changes to wasm debugger for UI integration
2019-03-28 kjlubick@google.com Support WebGL 1.0 with caps
2019-03-28 kjlubick@google.com Add gen_interface to CheckGeneratedFiles check
2019-03-28 bungeman@google.com SkTLazy constructors to require constructable.
2019-03-28 brianosman@google.com Improve color space logic in read/writeSurfacePixels
2019-03-28 kjlubick@google.com Add test_only option to gen_interface
2019-03-28 skia-autoroll@skia-public.iam.gserviceaccount.com Roll third_party/externals/swiftshader 94f195b18776..0839cbda698f (2 commits)

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 (stani@google.com), and stop
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The DartPersistentValue used to hold the image callback is tied to a
Dart isolate.  Destructing the DartPersistentValue requires entering
the isolate and must be done on the UI thread.

Fixes https://github.com/flutter/flutter/issues/29379

Using one global resource loading context will fail if two PlatformViews are
running concurrently with two different IO threads.

Also cleans up the a11y unittests to use the new builder API and avoids polluting the global namespace with state for assertions.

a977273262 Re-allow the incremental compiler to load modules
7b33a8fdc4 [cfe] Fix type inference in map literals with spreads
864b22d3ce [cfe] Add inference and type checks to if-elements in maps

https://skia.googlesource.com/skia.git/%2Blog/e51181387f76..05be23dbd3c4

git log e51181387f763864acf5be828831b2d7c2b29065..05be23dbd3c4565cb23744c154df80b0ebc0208a --date=short --no-merges --format=%ad %ae %s
2019-03-28 reed@google.com use mixer to combine two filters
2019-03-28 kjlubick@google.com Add GrCap for initializing textures
2019-03-28 bsalomon@google.com Don't limit glTexStorage performance workaround on Android to command buffer.
2019-03-28 mtklein@google.com try purging between benches
2019-03-28 mtklein@google.com bool SkColorSpaceXformSteps::Required()
2019-03-28 egdaniel@google.com Add support to disable vsync on mac viewer.
2019-03-27 recipe-mega-autoroller@chops-service-accounts.iam.gserviceaccount.com Roll recipe dependencies (nontrivial).
2019-03-28 bratell@opera.com Add an include guard to SkottieShaper.h

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 (stani@google.com), and stop
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05f3b12960 Add test for native declarations
b978fdd142 Move experimental flag defaults to CFE
cc00203310 Update pub client version
3e4a1de6e9 Use dart:foo-patch import uri for patches; remove VM workaround for sdk uris
cf768254fd Temporarily disable 'Allow the incremental compiler to load modules'
7baae76480 Always use ir constants in annotations when constant-update-2018 is enabled
10abacba10 Use hasOnlyNonDeferredImportPathsToConstant to add deferred constants
32a5fa0a83 Allow incremental compiler to just create outline
83e6e9f8e6 Allow the incremental compiler to load modules
ef168de000 [vm/kernel] Index all source and line starts before using them (2nd try)
add5a27120 [infra] Add `constant-update-2018` flag to v2.3 lang features tests

https://skia.googlesource.com/skia.git/%2Blog/3240800a9487..e51181387f76

git log 3240800a9487b736fa268f10c3f5dc0612dbc39d..e51181387f763864acf5be828831b2d7c2b29065 --date=short --no-merges --format=%ad %ae %s
2019-03-28 skia-autoroll@skia-public.iam.gserviceaccount.com Roll third_party/externals/angle2 208af3ebda25..e810ad90799c (10 commits)
2019-03-28 skia-autoroll@skia-public.iam.gserviceaccount.com Roll third_party/externals/swiftshader 57e05b8be2d9..94f195b18776 (1 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 (stani@google.com), and stop
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https://skia.googlesource.com/skia.git/%2Blog/01a065884b7d..3240800a9487

git log 01a065884b7d0a1fe563007e72bbf2793727c5f4..3240800a9487b736fa268f10c3f5dc0612dbc39d --date=short --no-merges --format=%ad %ae %s
2019-03-28 skia-recreate-skps@skia-swarming-bots.iam.gserviceaccount.com Update go_deps asset
2019-03-28 skia-autoroll@skia-public.iam.gserviceaccount.com Roll third_party/externals/swiftshader 179c932426b3..57e05b8be2d9 (1 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 (stani@google.com), and stop
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