On Android we were never deleting the textures allocated for
the texture registry, which resulted in a memory leak, see:
https://github.com/flutter/flutter/issues/24145

Added `FlutterPluginRegistrantCallback` typedef and optional `setPluginRegistrantCallback` static method in `FlutterPlugin`. `setPluginRegistrantCallback` is used to set a callback defined in AppDelegate.m which registers some subset of plugins with a `FlutterPluginRegistry` (for example, a headless FlutterEngine). This allows for plugins which utilize background execution functionality to enable the use of other plugins on the background isolate. This puts iOS on par with Android for background execution.

Along with updated examples and Medium posts, this fixes [flutter/flutter#21925](https://github.com/flutter/flutter/issues/21925).

https://skia.googlesource.com/skia.git/%2Blog/154acd7a1374..be9aff25bddc

git log 154acd7a137438b2e7f0c7c1803a3e9d969e867c..be9aff25bddc3eecf84d9c37af222ea40c261cb1 --date=short --no-merges --format=%ad %ae %s
2019-02-15 robertphillips@google.com Remove GrContextPriv.h from GrRenderTargetContext.h
2019-02-14 herb@google.com Reland "Use bulk interface for paths"
2019-02-15 halcanary@google.com SkPDF: simplify subsetting code
2019-02-15 skia-autoroll@skia-public.iam.gserviceaccount.com Roll ../src b698b62f407e..5862f084f69f (425 commits)
2019-02-15 herb@google.com Revert "Use bulk interface for paths"
2019-02-15 brianosman@google.com Add curve visualization back, guard eval
2019-02-15 herb@google.com Revert "Calculate strike in path case"
2019-02-15 bsalomon@google.com Add option to force GLSL string caching rather than program binaries.
2019-02-14 robertphillips@google.com Switch GPU blur code over to using GrRecordingContext
2019-02-15 bsalomon@google.com Add SK_API to GrContextOptions and GrContextOptions::PersistentCache
2019-02-15 bsalomon@google.com Remove unused fields related to old multitexturing TextureOp.
2019-02-15 skia-autoroll@skia-public.iam.gserviceaccount.com Roll third_party/externals/angle2 559aaca5abd8..aead8edf8c46 (1 commits)
2019-02-14 brianosman@google.com New SkCurve type with multiple curve segments

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

Also extend the embedder unit tests to cover AOT execution

https://skia.googlesource.com/skia.git/%2Blog/7a74c7cb6da0..154acd7a1374

git log 7a74c7cb6da0809e2ea2121932b889844e249157..154acd7a137438b2e7f0c7c1803a3e9d969e867c --date=short --no-merges --format=%ad %ae %s
2019-02-15 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

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

https://skia.googlesource.com/skia.git/%2Blog/b00f7b34751b..7a74c7cb6da0

git log b00f7b34751b64a7dc3051e452f5a63afe222891..7a74c7cb6da0809e2ea2121932b889844e249157 --date=short --no-merges --format=%ad %ae %s
2019-02-15 skia-autoroll@skia-public.iam.gserviceaccount.com Roll third_party/externals/angle2 77874e2ca341..559aaca5abd8 (4 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 (stephana@google.com), and stop
the roller if necessary.

https://skia.googlesource.com/skia.git/%2Blog/9a88bee122f1..b00f7b34751b

git log 9a88bee122f145014ce246ba872b1738b79efe83..b00f7b34751b64a7dc3051e452f5a63afe222891 --date=short --no-merges --format=%ad %ae %s
2019-02-14 skia-autoroll@skia-public.iam.gserviceaccount.com Roll third_party/externals/swiftshader de16f327d051..2bb0864b22e7 (1 commits)
2019-02-14 bungeman@google.com Fix signed/unsigned mismatch in shaper assert.
2019-02-14 bungeman@google.com Fix assert in shaper.
2019-02-14 robertphillips@google.com Allow GrRecordingContext to create surfaceContexts
2019-02-14 bungeman@google.com Remove typeface from SkShaper constructor.
2019-02-14 herb@google.com Calculate strike in path case
2019-02-13 bungeman@google.com Add HarfBuzz callbacks.
2019-02-14 bungeman@google.com Fix calculating clusters from start of input.
2019-02-14 jvanverth@google.com Add MoltenVK support to Viewer.
2019-02-13 michaelludwig@google.com Clean up GrQuad ctors
2019-02-14 nigeltao@google.com Have Wuffs output to BGRA, not indexed color
2019-02-14 herb@google.com Use bulk interface for paths
2019-02-14 brianosman@google.com Various particle system improvements
2019-02-14 recipe-roller@chromium.org Roll recipe dependencies (trivial).
2019-02-14 brianosman@google.com Particles/SkReflected: Generalize array reflection
2019-02-14 skia-autoroll@skia-public.iam.gserviceaccount.com Roll third_party/externals/angle2 52047de4d41f..77874e2ca341 (1 commits)
2019-02-14 bsalomon@google.com Use destructors to free resources owned by lazy proxy callbacks
2019-02-14 bungeman@google.com Don't respect FontConfig matrix for bitmap fonts.
2019-02-14 fmalita@chromium.org [SVGCanvas] Clean up public factories
2019-02-14 bungeman@google.com Defer loading particle effect to load time.
2019-02-14 robertphillips@google.com Baulk at creating wait semaphores if we can't always delete them
2019-02-13 michaelludwig@google.com Add blendmode to GrRTC::drawTexture
2019-02-14 egdaniel@google.com Use kRGB_888x_SkColorType when importing R8G8B8X8 AHB.
2019-02-14 recipe-roller@chromium.org 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 (stephana@google.com), and stop
the roller if necessary.

(Authored by @nathanrogersgoogle )

https://skia.googlesource.com/skia.git/%2Blog/a0dcd29f536b..9a88bee122f1

git log a0dcd29f536b195681684b3105842970d82383a5..9a88bee122f145014ce246ba872b1738b79efe83 --date=short --no-merges --format=%ad %ae %s
2019-02-14 skia-autoroll@skia-public.iam.gserviceaccount.com Roll ../src 1f0e830f475f..b698b62f407e (516 commits)
2019-02-14 halcanary@google.com resources: add text for testing shaper
2019-02-14 egdaniel@google.com Add kRGB_888X_GrPixelConfig
2019-02-14 rmistry@google.com Bring back PerCommit-Bookmaker to the waterfall

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

https://skia.googlesource.com/skia.git/%2Blog/6152470dc69e..a0dcd29f536b

git log 6152470dc69ee96172e5f4c3270f98e47ff9693d..a0dcd29f536b195681684b3105842970d82383a5 --date=short --no-merges --format=%ad %ae %s
2019-02-14 zhuo@hexoasis.com Fix bug of the destructor of SkSVGDevice
2019-02-13 reed@google.com Update examples to use SkFont

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

https://skia.googlesource.com/skia.git/%2Blog/4037f7f5d8b4..6152470dc69e

git log 4037f7f5d8b465f50f28135bfe0e532e2154089f..6152470dc69ee96172e5f4c3270f98e47ff9693d --date=short --no-merges --format=%ad %ae %s
2019-02-14 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

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

https://skia.googlesource.com/skia.git/%2Blog/09c01e9df260..4037f7f5d8b4

git log 09c01e9df260053399eb22efcfd6b248d66a2492..4037f7f5d8b465f50f28135bfe0e532e2154089f --date=short --no-merges --format=%ad %ae %s
2019-02-14 skia-autoroll@skia-public.iam.gserviceaccount.com Roll third_party/externals/angle2 6fc22a13d45d..52047de4d41f (3 commits)
2019-02-13 reed@google.com remove unused variable
2019-02-13 zhuo@hexoasis.com Fix bug of SkSVGCanvas::Make

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

https://skia.googlesource.com/skia.git/%2Blog/186669c4128b..09c01e9df260

git log 186669c4128bf9de63453e238d7c2e6ffbf34bca..09c01e9df260053399eb22efcfd6b248d66a2492 --date=short --no-merges --format=%ad %ae %s
2019-02-13 rmistry@google.com Make Housekeeper-PerCommit-Bookmaker a tryjob only bot
2019-02-13 herb@google.com Remove empty processing from drawGlyphRunAsBMPWithPathFallback
2019-02-13 recipe-roller@chromium.org Roll recipe dependencies (trivial).
2019-02-13 brianosman@google.com Use half-floats for out-of-gamut color in GrAAFillRRectOp
2019-02-13 nigeltao@google.com Keep scaledHeight calculation across oID calls

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

c92d5ca288 Migrate ClassElementImplTest from task model.
d566a674d0 Revert "[standalone] Name dart:io threads."
cc3218b771 [standalone] Name dart:io threads.
525b43d747 [vm] Decouple intrinsifier code from runtime
4510fa08ca [vm / library] reduce dart:ffi test recursion depth
def7e2dac7 Migrate ConstantVisitorTest from task model.
010a12330e [vm] Fix ThrowErrorSlowPath-derived instructions (e.g. CheckNull) in JIT mode.
76f531e742 [vm / library] dart:ffi status file entry for flaky dartkb crash
c8a2a7b719 [vm/ffi] Move FFI transformations from pkg/kernel to pkg/vm.
7fe7e28c46 [vm] Fix location of Flutter 3xH patch file.
d1bf6ae7d2 Track nonNullIntent in unconditional control flow.
13c4b160ba Add migration tool support for bare "return;" statements
3796dd8ba1 [vm] Pass --enable-asserts to analyze.dart in analyze_flutter.sh.
809d8123d3 [vm] Add FFI library to more targets and Flutter file libraries.json (in patch).
d6a763ebd1 [vm / library] dart:ffi fix android build
cf5a7cf36a Simplify class_hierarchy_test: Move tests of getLegacyLeastUpperBound to own file
a92ddcf34b Add package:expect/matchers_lite.dart
0dfac95dac Simplify class_hierarchy_test: don't use package:test
5bf0065b46 Simplify class_hierarchy_test: don't use package:test_reflective_loader
f954c0535c Simplify class_hierarchy_test: remove abstract class
a200ef3124 Don't include main in computeTransitiveClosure
0651c8c4fd [vm / library] dart:ffi status file entry for reload crash
4fa1e3a3ca [vm / library] dart:ffi status file entry for appjitk crashes
3236ac15a1 Fix flutter-analyze bot.
3196b87f10 Incremental compiler: Include right libraries when entry point is translated
e6a181a583 Add set literal release comment to changelog.
7d46d4b5cb [vm / library] Foreign function interface prototype
671865cd1a Fix JSON parser.
bffa51efa2 Add ClassHierarchyBuilder.getKernelTypeAsInstanceOf
857d834e64 Remove obsolete expectMoreSpecific parameter
9c1b50b1aa Copy inferred mixin application type arguments to builder hierarchy
f815b4cba7 Add Loader.computeTypeBuilder
a31a72521b Don't include declarations of the library itself.
c8b28c4cf9 [vm/compiler] graph checker addition
f21fafd411 Migrate SimpleResolverTest from task model.
80e43c6a75 Remove the Modification class; use SourceEdit instead.
3e5a4f1a5d Sort declarations in file inferred_type_test.dart
1e72e9c985 Fix tests now that set literal support is enabled by default.
f841096701 Fix for crash if MixinDeclaration has a const constructor.
80c8848624 Support for enums in available suggestions, getDetails, boost relevance.
6588eaf794 Fix calls to generator-bodies to correctly model elided parameters
3f96de7855 Cleanup intermediate control flow collection structures in AstBuilder
ca32bef641 Add migration support for the `@required` annotation.
8d5958bd9a Migrate ErrorResolverTest.
9d280198a4 Prepare to publish analyzer version 0.35.1.
135abb41f7 Migrate ElementResolverCodeTest from task model.
6d2daa692c Set non_nullable experiments flag during migration tests.
c507acfae4 Fix Js-interop factory calls which broke when eliding optional parameters.
0541640e37 [testing] Create list from test list iterable
66c404a26e dart2js: Reduce assert helpers
c812d5a373 Fix available suggestions tests on Windows.
78509055b6 [vm] Add names for more types to the V8 snapshot profile output.
80e85d06ab Fixes for enum constants in available declarations.
cccaae2b01 bump to linter 0.1.82
5fe0202b0b Unify MapElement and CollectionElement
92227c05fc [infra] Remove ContentShell support in test driver interface js.
f54650ccaf Add LineInfo to Declaration search results
ce91bcb442 Add migration support for named parameters.
69589be237 [infra] Rename analyzer-stable branch builders to have branch suffix.
ed5bdfa227 [CFE] Fix check for unavailable constructors.
660cf26dbb Reland "[vm] Decouple stub code from runtime"
250f9665fb [CFE] Get constants backend from backend target.
b7afb22323 [CFE] Eliminate redundant coreTypes parameter.
44681fa98e [CFE] Move DDC specific behavior into ConstantsBackend.

* Begin space tracking metrics in LibTxt.

* Add tracking for trailing whitespace.

* Store is_ghost in BidiRun

* Add comments

0a7dcf17eb Attempt tracing to /sys/kernel/tracing/trace_marker on Linux.
02b65ee478 Include 'includedSuggestionRelevanceTags' into completion response.
71e8588399 Include enum constants into available declarations.
30f9143831 Revert "[vm] Decouple stub code from runtime." and "[VM/Decoupling] Follow-up change to decoupling of stub_code: Fix missing "!""

https://skia.googlesource.com/skia.git/%2Blog/b6f53783337e..186669c4128b

git log b6f53783337e096d6803ba3907044b79b4ac9f6c..186669c4128bf9de63453e238d7c2e6ffbf34bca --date=short --no-merges --format=%ad %ae %s
2019-02-13 reed@google.com work to fix bookmaker
2019-02-13 jvanverth@google.com Fix drag events in Mac viewer.
2019-02-13 herb@google.com Use SkStrikeSpec to consolidate SkDescriptor, Effects and Typeface.
2019-02-13 mtklein@google.com rewrite SkMasks::CreateMasks to work in bytesPerPixel
2019-02-13 skia-autoroll@skia-public.iam.gserviceaccount.com Roll third_party/externals/angle2 d3fac74a236e..6fc22a13d45d (7 commits)
2019-02-13 mtklein@google.com add Windows -Wuffs builders
2019-02-13 reed@google.com fix contour-measure for move-line-move
2019-02-13 robertphillips@google.com Switch path renderers over to using GrRecordingContext

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

https://skia.googlesource.com/skia.git/%2Blog/94a5328e0e4b..b6f53783337e

git log 94a5328e0e4b59286ec0e04e0fabe6a447451f30..b6f53783337e096d6803ba3907044b79b4ac9f6c --date=short --no-merges --format=%ad %ae %s
2019-02-13 halcanary@google.com SkShaper: enable for unit and render tests
2019-02-13 reed@google.com fix rawiter::peek
2019-02-12 robertphillips@google.com Switch Ops over to using GrRecordingContext
2019-02-13 skia-autoroll@skia-public.iam.gserviceaccount.com Roll ../src 77b5d9247fd7..1f0e830f475f (486 commits)
2019-02-12 scroggo@google.com Blacklist Codec tests on Wuffs bot
2019-02-13 skia-autoroll@skia-public.iam.gserviceaccount.com Roll third_party/externals/swiftshader 73c3124cc249..de16f327d051 (1 commits)
2019-02-12 ethannicholas@google.com added constant 0 and 1 swizzle components to SkSL
2019-02-13 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

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

https://skia.googlesource.com/skia.git/%2Blog/66f09a72995a..94a5328e0e4b

git log 66f09a72995a761bb9bde11b0e378ce84b84bae9..94a5328e0e4b59286ec0e04e0fabe6a447451f30 --date=short --no-merges --format=%ad %ae %s
2019-02-12 benjaminwagner@google.com Add Ubuntu18 Calmbench and Valgrind jobs

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

Uses SetClipPlanesCmd in addition to the old clipping approach.
Flutter will use both clipping methods during a transition period
(Scenic will select internally which one to use).

https://skia.googlesource.com/skia.git/%2Blog/14d64dd4c47c..66f09a72995a

git log 14d64dd4c47c2ecf45e8b9e02b264fcd5eea7b09..66f09a72995a761bb9bde11b0e378ce84b84bae9 --date=short --no-merges --format=%ad %ae %s
2019-02-12 mtklein@google.com replace gamma_correct with gamut/transfer_fn in DM
2019-02-12 recipe-roller@chromium.org Roll recipe dependencies (trivial).
2019-02-12 herb@google.com Inline allocateNewGlyph
2019-02-12 bungeman@google.com Font fallback to handle no font with character.
2019-02-12 skia-autoroll@skia-public.iam.gserviceaccount.com Roll third_party/externals/angle2 c66fb571be1a..d3fac74a236e (8 commits)
2019-02-12 fmalita@chromium.org [sksg] Fix group hit-testing order
2019-02-12 reed@google.com update sample-sg with hittesting
2019-02-12 bungeman@google.com Check both thickness and position in gm.

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

https://skia.googlesource.com/skia.git/%2Blog/0b6ae6386d34..14d64dd4c47c

git log 0b6ae6386d34efa7554d1b515c016f1c66e09a30..14d64dd4c47c2ecf45e8b9e02b264fcd5eea7b09 --date=short --no-merges --format=%ad %ae %s
2019-02-12 herb@google.com Remove unneeded SkPackedUnicharID
2019-02-12 recipe-roller@chromium.org Roll recipe dependencies (trivial).
2019-02-12 egdaniel@google.com Remove private configs from GrPixelConfig.
2019-02-12 halcanary@google.com SkPaint: clean up ctor, dtor, etc
2019-02-12 brianosman@google.com Experimental Particle System
2019-02-12 bungeman@google.com Primitive SkShaper to do primitive line breaking.
2019-02-12 reed@google.com starter sample for playing with SG. will flesh out more over time.
2019-02-12 bungeman@google.com Make SkSpan C++11 compatible.
2019-02-12 benjaminwagner@google.com Upgrade to Mesa 18.3.3
2019-02-12 herb@google.com Remove redundant fGlyphMap.set

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

This reverts commit c4a55552.

https://skia.googlesource.com/skia.git/%2Blog/63d477cd99b0..0b6ae6386d34

git log 63d477cd99b0706262a284a03cba859d0f19d638..0b6ae6386d34efa7554d1b515c016f1c66e09a30 --date=short --no-merges --format=%ad %ae %s
2019-02-12 skia-autoroll@skia-public.iam.gserviceaccount.com Roll third_party/externals/swiftshader 0f34a98a206d..73c3124cc249 (1 commits)
2019-02-12 recipe-roller@chromium.org Roll recipe dependencies (trivial).
2019-02-12 skia-autoroll@skia-public.iam.gserviceaccount.com Roll third_party/externals/swiftshader f96948857780..0f34a98a206d (1 commits)
2019-02-12 fmalita@chromium.org [sksg] Hit-testing API
2019-02-12 skia-autoroll@skia-public.iam.gserviceaccount.com Roll ../src 35663ddf4997..77b5d9247fd7 (472 commits)
2019-02-08 ethannicholas@google.com SkSL Metal backend can now handle CCPR
2019-02-12 kjlubick@google.com Build code size treemaps for skottie_tool
2019-02-11 gkaiser@google.com SkUTF: Avoid potential nullptr dereference
2019-02-12 recipe-roller@chromium.org 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 (stephana@google.com), and stop
the roller if necessary.

https://skia.googlesource.com/skia.git/%2Blog/217acf58d0d8..63d477cd99b0

git log 217acf58d0d80c50854c1fd8f6684c325d8d6de6..63d477cd99b0706262a284a03cba859d0f19d638 --date=short --no-merges --format=%ad %ae %s
2019-02-12 skia-autoroll@skia-public.iam.gserviceaccount.com Roll third_party/externals/angle2 ad194995ed72..c66fb571be1a (2 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 (stephana@google.com), and stop
the roller if necessary.