move web_ui to NNBD syntax

Correctly describe the way aspect ratio is managed when one parameter is not specified.

Reverting for b/158816279

dart-lang/sdk@6d4e7d6830 Fix an exception thrown when a method cannot be resolved because the target type is dynamic
dart-lang/sdk@7fce125300 [cfe,kernel] Add AstPrinter
dart-lang/sdk@b2d41ab0a2 [infra] Update checked-in SDKs to 2.9.0-16.0.dev
dart-lang/sdk@25f2f7796a Send LSP outlines for all open files
dart-lang/sdk@e1d1adce17 pkg:native_stack_trace - fix sdk version range
dart-lang/sdk@efcb8f9213 Migrator: Do not connect return values to return types on generators
dart-lang/sdk@61184814e2 Migrator: use `dart pub` to check outdated
dart-lang/sdk@1a2cbd54d7 [co19] Enable migrated Language/Classes tests
dart-lang/sdk@6f83a5ff9b [vm/aot] Add a GNU build ID to direct-to-ELF snapshots.
dart-lang/sdk@2e939f215a [vm/aot] Move ELF section manipulation out of CreateAppAOTSnapshotAsElf.
dart-lang/sdk@261e283a0a [cfe] Handle explicit type parameter type nullability in bounds
dart-lang/sdk@21222b64c4 Revert "[vm] Build dart2native dependencies with the normal "create_sdk" target"
dart-lang/sdk@f369194255 [cfe] Add test for extension on Never
dart-lang/sdk@967deb8db4 Revert "[vm, timeline] Fix compilation failed below macOS 10.14"
dart-lang/sdk@156ef76535 [vm, timeline] Fix compilation failed below macOS 10.14
dart-lang/sdk@6021f0aec2 Follow up on https://dart-review.googlesource.com/c/sdk/+/151343, assertOrder() now accepts the order with current.relevance > previous.relevance instead of current.relevance >= previous.relevance, additional tests use assertOrder([]).
dart-lang/sdk@c68c06996a prefer “exclude” language for excluded entities
dart-lang/sdk@09ea885dcd [testing] Rename dart2js filesets more generically.
dart-lang/sdk@3798e5c2f0 [dart2js] Fix some compilation errors in dart2js/native.
dart-lang/sdk@0d3e77d28e Start converting assists to CorrectionProducer
dart-lang/sdk@7f6b0d82eb Issue 42337. Report BODY_MIGHT_COMPLETE_NORMALLY for factory constructors.
dart-lang/sdk@18b753cbcd Support for null-aware ExtensionOverride.
dart-lang/sdk@d39d4d0d55 Revert "Add an --os=fuchsia option to build.py:"
dart-lang/sdk@047f1721a1 Remove the DartCompletionManagerTest and replace it with CompletionRelevanceTest, making all of the completion relevance tests consistent.
dart-lang/sdk@b65c90a07a [dart:io] Fix _connecting counting in HttpClient
dart-lang/sdk@bd3b3299cb Correct an abbreviation
dart-lang/sdk@badc77239a [vm/aot] Avoid unbinding canonical names in AOT transformations
dart-lang/sdk@66cd5d9cc7 [dart:io] Update inaccurate comments of writeByteSync
dart-lang/sdk@85f6c01fc4 Migrate language_2/subtyping_static to NNBD.
dart-lang/sdk@f2fafcd440 Extract and reuse EnclosingExecutableContext.displayName
dart-lang/sdk@48f20c64c6 [vm/benchmark] Fix metric type of GenKernelKernelMaxRSS benchmark
dart-lang/sdk@4ce18ab931 Add an --os=fuchsia option to build.py:
dart-lang/sdk@d2543e32f4 Migrate standalone tests which rely on the pre-nnbd sdk libraries.
dart-lang/sdk@9a87cf9174 Revert "[vm] Check prefix.loadLibrary is called and returns before prefix members are used."
dart-lang/sdk@5619ec500e prefer “exclude” language for excluded entities
dart-lang/sdk@cf1681e11e [dart2js] Remove more unused old rti helpers
dart-lang/sdk@920ddae937 Re-write of the computation of the context type for code completion.  Instead of passing a parent and child node, a parent node with an offset is passed.  The primary purpose of this change was to fix a bug with argument lists which is close to being fixed.
dart-lang/sdk@459255ab09 Migrator: Fix navigating to top-of-file
dart-lang/sdk@25cf204dd2 Prevent duplicate code actions for lines with multiple similar errors
dart-lang/sdk@16ef3ee562 Fix LSP equality checks for lists/maps within unions
dart-lang/sdk@3b243a0c30 Recurse through lists/maps when generating hash codes in LSP types
dart-lang/sdk@48f2d10d3e Deprecate ClassElement.hasReferenceToSuper
dart-lang/sdk@b7efcd276c Report NO_COMBINED_SUPER_SIGNATURE.
dart-lang/sdk@a1fc2ea80c Make variables assigned in a loop not definitely unassigned anywhere in the loop.
dart-lang/sdk@28231a790b Analyzer: regenerate diagnostics.md
dart-lang/sdk@60ec2b31e6 [dart2js] More sharding of rti_need and rti_emission tests
dart-lang/sdk@9b4b9ae3a7 [cfe] Fix expectations after adding of FutureOrType
dart-lang/sdk@2fbe5c1f54 Migration: Make the three migration phases explicit in NonNullableFix API.
dart-lang/sdk@9f8776f4a9 Migration: split out a MigrationCliRunner API from MigrationCli.
dart-lang/sdk@a7c93201e4 Migration: rework how MigrationCli.run() reports an exit code.
dart-lang/sdk@a88a328b7f [vm] Build dart2native dependencies with the normal "create_sdk" target
dart-lang/sdk@68e17083b9 [co19] Enable Subtyping tests
dart-lang/sdk@294a2cffd1 Analyzer: print constructor name when constructor returns invalid type
dart-lang/sdk@d87046342f [benchmarks/ffi] Add FfiCall benchmark with Handles
dart-lang/sdk@28606d040b [cfe] Recompute type parameter type nullability after substitution
dart-lang/sdk@929d5e4a98 [cfe,ddc,dart2js,vm] Add FutureOrType
dart-lang/sdk@8d4d3a33ad [vm] fix build CIPD package issue
dart-lang/sdk@7c10084b94 Migrate language_2/static to NNBD.
dart-lang/sdk@755686e5b2 [vm] Simplify RemoveRedefinitions.
dart-lang/sdk@68ede604ce [vm] Roll third_party/icu@ to 8d29692df64066
dart-lang/sdk@b35f03471f [vm] Roll third_party/boringssl@ to 429ccb1877f798
dart-lang/sdk@b0d4c359d8 Move tests for 4 codes to diagnostics directory.
dart-lang/sdk@8d08bbf40a Add a fix for default_list_constructor
dart-lang/sdk@32a93e2147 Analyzer: Remove error on class-used-as-mixin referencing super
dart-lang/sdk@3dc27a55fa Migrator: Add a failing test for #42327
dart-lang/sdk@67539c2faf Migrate language_2/regress to NNBD.
dart-lang/sdk@84d3f3681f [dart2js] pass `null` for missing required argument in weak mode
dart-lang/sdk@213f805294 Migrator: Bump highlight.js to 10.1.0
dart-lang/sdk@c22dc20a93 Use the const-ness of an element when completing in a const context using available declarations
dart-lang/sdk@b907f9928f Migrator: Begin flow analysis on top-level annotations
dart-lang/sdk@89fc3e1269 [vm/switchable_call] Refactor SwitchableCallHandler so that resolution is done outside of RunWithStoppedMutators.
dart-lang/sdk@ce90061e27 Migrate language_2/setter to NNBD.
dart-lang/sdk@b1442a1f9a Remove unused import
dart-lang/sdk@af054ee91c Adjust documentation to various functions
dart-lang/sdk@542563106b [vm] Always inline List.generate
dart-lang/sdk@fda4238285 During linking, resolve initializers of constant variables with flow analysis.
dart-lang/sdk@24852421e2 Change method override inference to use combined member signature.
dart-lang/sdk@43131b575e Migration: fix crashes with `extension Foo<T extends ...> on T`
dart-lang/sdk@6f4bc6a9be Add test for mixin application constructor forwarding of default values.
dart-lang/sdk@9be1160700 Do not suggest the keyword const when completing in a constant context
dart-lang/sdk@3a31bc2fd4 Update relevance metrics to compute element kind probabilities based on whether type parameters are in scope
dart-lang/sdk@56dbe294f2 Analyzer: Do not report const constructors with mixed in synthetic fields
dart-lang/sdk@fa68d27ef7 [infra] Add explanation to ABI test logs
dart-lang/sdk@e601ca5e45 Updates documentation of StreamController.close and .done.
dart-lang/sdk@fc1ecdae0d [vm] Fix extra output in assembly DWARF.
dart-lang/sdk@2f2efeb07a Filter LSP definitions to not include variable names
dart-lang/sdk@7b12c8e06d Add fixes for extends_non_class
dart-lang/sdk@44f869d3a6 Cap the amount of time spent waiting for plugin completions in LSP
dart-lang/sdk@99bd9d7db5 [vm, gardening] Initialize target array in movs tests to satisfy msan.
dart-lang/sdk@e160698933 [vm/aot] Delay relocated address calculation for static symbols.
dart-lang/sdk@6544c69e23 [vm/ffi] Convert Objects to Dart_Handles in FFI calls
dart-lang/sdk@bf3166be17 [infra] Shard VM and CFE nnbd builders more
dart-lang/sdk@50836c171e [parser] Fix parsing of empty index in cascade
dart-lang/sdk@a3eacf734e Revert "File::Copy avoids direct copying on Windows"
dart-lang/sdk@bbeda37c05 Address review comments from 150935
dart-lang/sdk@c1f0bc310d [vm/concurrency] When waking up ThreadInterrupter first check if it is shutdown already.
dart-lang/sdk@0b64f54889 [VM/nnbd] Normalize 'X extends Never' to 'Never'.
dart-lang/sdk@d25c369f3e Migrate language_2/script to NNBD.
dart-lang/sdk@a13a2d7c84 Redo "[dart2js] Delete unused old-rti helpers"
dart-lang/sdk@a39a3cd141 [dart:html] Add rename/metadata for some attributes
dart-lang/sdk@5af38092e3 [dart:html] Add track event to RTCPeerConnection
dart-lang/sdk@c607eb9637 [nnbd_migration] address an issue with the progress text written to stdout
dart-lang/sdk@ccb380117c Migrate language_2/set_literals to NNBD.
dart-lang/sdk@348499d92d [vm/concurrency] Remove ASSERT from IsMutatorThread to address r/w race isolate_ in vm thread.
dart-lang/sdk@c54ec8d5f3 [ package:dds ] Handle expression evaluation invocations in DDS and forward `compileExpression` calls to clients which provide their own compilation service.
dart-lang/sdk@f0ea02bc51 [vm/nnbd] Do not trust non-nullable Object for parameter of operator==
dart-lang/sdk@9f6c372228 Analyzer: forward const constructors to mixin apps as const
dart-lang/sdk@1ce143cfc1 Issue 42278. Null-nullify types after function expression inference, not the context type.
dart-lang/sdk@ccc39d5798 For FunctionExpression inference check for null subtype explicitly.
dart-lang/sdk@f46efc71c2 [VM/nnbd] Do not apply legacy erasure to type literals.
dart-lang/sdk@ab034e69b4 [dart2js] Fix reduction to declared type in type promotion computation
dart-lang/sdk@eb21b006ac Improve the changelog entry for linter
dart-lang/sdk@6a36dbad2e Clarify deprecation notices for package:analyzer/analyzer.dart
dart-lang/sdk@32559d3799 Analyzer: Do not forward factory constructors to mixin applications
dart-lang/sdk@9f6510b31b [dart2js] Replace accesses to `options.nullSafetyMode` with `options.useLegacySubtyping` where possible.
dart-lang/sdk@6b40b26044 [nnbd_migration] Print warning when SDK_PATH is set and things go wrong.
dart-lang/sdk@6428bab7ed Add tests for override inherited inference.
dart-lang/sdk@67da8cf7f5 Fix for NPE when the assigned expression is synthetic at the end of the unit.
dart-lang/sdk@b19e9075db Non-nullify types after inference.
dart-lang/sdk@b0484ecbde [vm] Check prefix.loadLibrary is called and returns before prefix members are used.
dart-lang/sdk@2a5c122d4a Migration: Fix EdgeBuilder._unimplemented if node==null
dart-lang/sdk@9f904ff184 [VM/runtime] Remove intermediate array copy step when rehashing types.
dart-lang/sdk@1f32f6563a Revert "[infra] Update checked-in SDKs to 2.9.0-15.0.dev"
dart-lang/sdk@5c3f9217cb Filter LSP completions (fuzzily) by prefix to reduce payload size
dart-lang/sdk@9e2f11251c Improve the message for default_list_constructor
dart-lang/sdk@20fb8cb737 Migrate language_2/rewrite to NNBD.
dart-lang/sdk@7c9f7f4bf8 [vm/aot] Fix UB behavior due to WriteFixed usage at unaligned positions.

As part of migrating Fuchsia from legacy SceneHost/ChildView based code
to Flutter Embedder based PlatformView, we need to expose the raw zircon
handle. Since we are converting a private getter to public getter, this
does not affect any existing code.
Co-authored-by: NSanjay Chouksey <sanjayc@google.com>

If this roll has caused a breakage, revert this CL and stop the roller
using the controls here:
https://autoroll.skia.org/r/fuchsia-linux-sdk-flutter-engine
Please CC wrightgeorge@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/ac16760df463..45fe2e8a9914

2020-06-12 herb@google.com move methods to options class
2020-06-12 fmalita@chromium.org [skjson] Reinstate initFastShortString
2020-06-12 egdaniel@google.com Add SkSurface flush call that takes a GrBackendSurfaceMutableState.
2020-06-12 johnstiles@google.com Allow printf-style formatting to be used in SK_ABORT.

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 bungeman@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

* Revert "Roll Dart SDK from 0b64f5488965 to 50836c171e91 (4 revisions) (#19017)"

This reverts commit f6455fa6.

* Revert "Roll Dart SDK from f0ea02bc51f8 to 0b64f5488965 (9 revisions) (#19013)"

This reverts commit 1f3aa23e.

* Revert "Roll Dart SDK from f043f9e5f6ea to f0ea02bc51f8 (22 revisions) (#19010)"

This reverts commit 5f37029a.

* Reland "Call Shell::NotifyLowMemoryWarning on Android Trim and LowMemory events (#18979)" (#19023)"

This reverts commit 0a852d8a.

This allows Fuchsia components executed by the Flutter runner to
specify a directory containing assets if they wish to store assets
separate from program data. This is specified in the program metadata
field within the component's specification with the new "assets"
attribute. If this attribute is absent, assets are loaded relative to
the path specified in the "data" attribute as before.

This is useful in the short term to use a location in the package where
we can store small files more efficiently. It is also potentially
useful longer term to enforce a stronger separatation between
executable program data and non-executable assets.

This commit adds some basic unit testing for the data parsing to the
flutter_runner_tests suite.

* onEndFrame JNI

* beginFrame brief change