Add a simple implementation that throws out all libraries and runs the
main method again which triggers all libraries to be initialized with
fresh values.
Move the hot reload tests to the ddc canary test configuration
since that is where the support works at this time.
Update frontend server to use the use the new version of the DDC
LibraryCompiler when the emit library bundle option is true.
Change-Id: I6eba613106672536ef8bfcb0ff0a55749e2fb63c
Reviewed-on: https://dart-review.googlesource.com/c/sdk/+/381902
Reviewed-by: Kevin Moore <kevmoo@google.com>
Reviewed-by: Nate Biggs <natebiggs@google.com>
Reviewed-by: Mark Zhou <markzipan@google.com>
Reviewed-by: Johnni Winther <johnniwinther@google.com>
This is a reland of commit d84f908641
Includes fixes:
--- Catch scope fix ---
Each catch block should define its own scope, but the compiler was not treating the body of these catch blocks as a scope. This was leading to incorrect variable renaming.
--- Duplicate label fix ---
Labels weren't being removed from the _labelNames Map after being used so multiple nodes were getting tagged with the same label. Note: This didn't actually cause any bugs because the label closer to the break statements using those labels was the correct one.
--- addAsyncCallback cleanup ---
The new async semantics actually don't require managing addAsyncCallback and removeAsyncCallback calls (proxies for async_helper.asyncStart and async_helper.asyncEnd). None of the other backends manage these themselves. It's up to tests to ensure they call async_helper.asyncStart and async_helper.asyncEnd.
Original change's description:
> [ddc] Update DDC compiler to start using the new async transform.
>
> Updates compiler.dart to use the new async transformation.
>
> Some key things to note:
> - Dart Let and BlockExpression expressions are represented as IIFEs in DDC compiled code. For non-async code this works fine but this doesn't work when they contain "await" expressions. When these expressions contain awaits we use the same lowering as we would for an async function, but instead apply it to the IIFE function. Then we simply await the IIFE Call expression as the IIFE will return a future after the transform.
> - For async/sync*/async* functions we want to make sure parameter initialization happens synchronously before any of the async logic is hit. To do this we first apply the async transform the user-code function body. We then prepend the paramter initialization logic to the body of the transformed function.
> - We add support for JS_RAW_EXCEPTION which allows the machinery in async_patch to access the wrapped JS exception in a catch block rather than the unwrapped Dart exception.
> - Stacktraces and sourcemaps have some differences. There is still room for improvement in these but they should at least allow users to reasonably step through parts of the async code.
>
>
> There are also several test fixes/updates associated with this change. The test_runner wrapper no longer has to inject in asyncStart/asyncEnd calls, these are handled by the new async logic.
>
> Change-Id: I0f9f547cd9eb52ff7d850d277876d4d57568a14e
> Reviewed-on: https://dart-review.googlesource.com/c/sdk/+/374444
> Reviewed-by: Bob Nystrom <rnystrom@google.com>
> Reviewed-by: Mark Zhou <markzipan@google.com>
> Reviewed-by: Johnni Winther <johnniwinther@google.com>
> Reviewed-by: Nicholas Shahan <nshahan@google.com>
Change-Id: Idfe05c0628b2b91f474d08d99427961381debeb5
Reviewed-on: https://dart-review.googlesource.com/c/sdk/+/376000
Reviewed-by: Johnni Winther <johnniwinther@google.com>
Reviewed-by: Bob Nystrom <rnystrom@google.com>
Reviewed-by: Mark Zhou <markzipan@google.com>
This reverts commit d84f908641.
Reason for revert: Causing internal failures.
Original change's description:
> [ddc] Update DDC compiler to start using the new async transform.
>
> Updates compiler.dart to use the new async transformation.
>
> Some key things to note:
> - Dart Let and BlockExpression expressions are represented as IIFEs in DDC compiled code. For non-async code this works fine but this doesn't work when they contain "await" expressions. When these expressions contain awaits we use the same lowering as we would for an async function, but instead apply it to the IIFE function. Then we simply await the IIFE Call expression as the IIFE will return a future after the transform.
> - For async/sync*/async* functions we want to make sure parameter initialization happens synchronously before any of the async logic is hit. To do this we first apply the async transform the user-code function body. We then prepend the paramter initialization logic to the body of the transformed function.
> - We add support for JS_RAW_EXCEPTION which allows the machinery in async_patch to access the wrapped JS exception in a catch block rather than the unwrapped Dart exception.
> - Stacktraces and sourcemaps have some differences. There is still room for improvement in these but they should at least allow users to reasonably step through parts of the async code.
>
>
> There are also several test fixes/updates associated with this change. The test_runner wrapper no longer has to inject in asyncStart/asyncEnd calls, these are handled by the new async logic.
>
> Change-Id: I0f9f547cd9eb52ff7d850d277876d4d57568a14e
> Reviewed-on: https://dart-review.googlesource.com/c/sdk/+/374444
> Reviewed-by: Bob Nystrom <rnystrom@google.com>
> Reviewed-by: Mark Zhou <markzipan@google.com>
> Reviewed-by: Johnni Winther <johnniwinther@google.com>
> Reviewed-by: Nicholas Shahan <nshahan@google.com>
Change-Id: Ia939fe5a9dfd3a5031b06a7ea26c52e58b89f011
Reviewed-on: https://dart-review.googlesource.com/c/sdk/+/375701
Reviewed-by: Bob Nystrom <rnystrom@google.com>
Reviewed-by: Jake Macdonald <jakemac@google.com>
Commit-Queue: Nate Biggs <natebiggs@google.com>
Reviewed-by: Johnni Winther <johnniwinther@google.com>
Reviewed-by: Mark Zhou <markzipan@google.com>
Bot-Commit: Rubber Stamper <rubber-stamper@appspot.gserviceaccount.com>
Reviewed-by: Nicholas Shahan <nshahan@google.com>
Updates compiler.dart to use the new async transformation.
Some key things to note:
- Dart Let and BlockExpression expressions are represented as IIFEs in DDC compiled code. For non-async code this works fine but this doesn't work when they contain "await" expressions. When these expressions contain awaits we use the same lowering as we would for an async function, but instead apply it to the IIFE function. Then we simply await the IIFE Call expression as the IIFE will return a future after the transform.
- For async/sync*/async* functions we want to make sure parameter initialization happens synchronously before any of the async logic is hit. To do this we first apply the async transform the user-code function body. We then prepend the paramter initialization logic to the body of the transformed function.
- We add support for JS_RAW_EXCEPTION which allows the machinery in async_patch to access the wrapped JS exception in a catch block rather than the unwrapped Dart exception.
- Stacktraces and sourcemaps have some differences. There is still room for improvement in these but they should at least allow users to reasonably step through parts of the async code.
There are also several test fixes/updates associated with this change. The test_runner wrapper no longer has to inject in asyncStart/asyncEnd calls, these are handled by the new async logic.
Change-Id: I0f9f547cd9eb52ff7d850d277876d4d57568a14e
Reviewed-on: https://dart-review.googlesource.com/c/sdk/+/374444
Reviewed-by: Bob Nystrom <rnystrom@google.com>
Reviewed-by: Mark Zhou <markzipan@google.com>
Reviewed-by: Johnni Winther <johnniwinther@google.com>
Reviewed-by: Nicholas Shahan <nshahan@google.com>
This allows internal Set classes to be referenced by our runtime.
Context: incoming changes to our generic types (required for hot reload) requires that RTIs be passed to generic classes on instantiation. Moving our Set implementation into our private runtime and making their classes public allows us to directly reference them without clobbering names externally.
Change-Id: Ie47b3263ebbf2650d314b5285a2d50f3abd1a664
Reviewed-on: https://dart-review.googlesource.com/c/sdk/+/373327
Commit-Queue: Mark Zhou <markzipan@google.com>
Reviewed-by: Jens Johansen <jensj@google.com>
Reviewed-by: Nicholas Shahan <nshahan@google.com>
First of we apply the wanted lints etc we prefer.
This includes but isn't limited to using types (i.e. no "var") and
being explicit about creation (i.e. no missing "new").
Change-Id: I516bccdac9760221ea5311af4567466bb4a65c77
Reviewed-on: https://dart-review.googlesource.com/c/sdk/+/341960
Reviewed-by: Johnni Winther <johnniwinther@google.com>
Commit-Queue: Jens Johansen <jensj@google.com>
Reviewed-by: Alexander Thomas <athom@google.com>
Pure interfaces made `interface`s
implementation classes which cannot/should not be extended made `final`.
A class like `HasHMap` which provides the `Map` interface,
and no implementation except factory constructors
for internal implementations, is made `final`.
Unified {List,Set,Map}{Base,Mixin} into their `Base` class.
Deprecations are retained in comments for now, to be landed
separately. Search for '// TODO: @Deprecated'.
Tested: No new test, only adding restrictions on use.
CoreLibraryReviewExempt: Everybody's on vacation, everybody everywhere.
Change-Id: Ia83b8a3bb20b5b214546b328d4492de6658253db
Reviewed-on: https://dart-review.googlesource.com/c/sdk/+/288240
Reviewed-by: Aske Simon Christensen <askesc@google.com>
Reviewed-by: Martin Kustermann <kustermann@google.com>
Commit-Queue: Lasse Nielsen <lrn@google.com>
Reviewed-by: Nate Bosch <nbosch@google.com>
- Make previous behavior non-conditional
(already default and flag uses are removed)
- Use relative paths instead of package uris as module names
under --debugging-module-names flag, false by default.
(used as server paths in the browser, need to match relative
paths in source maps)
- Pass packageConfig to Javascript bundle API
- Add tests
Closes: https://github.com/dart-lang/sdk/issues/49667
Change-Id: I57c2e2629ba5dd756cce9a8ec6ae891fb092e1d9
Reviewed-on: https://dart-review.googlesource.com/c/sdk/+/255826
Commit-Queue: Anna Gringauze <annagrin@google.com>
Reviewed-by: Nicholas Shahan <nshahan@google.com>
Reviewed-by: Johnni Winther <johnniwinther@google.com>
Update the JavaScript bundler to maintain the state necessary for
the alternative invalidation strategy. This will provide the
javascript compiler with a single library component, so this must
handle re-combining this library with any SCC as well as keeping
the old summaries around.
Revived from https://dart-review.googlesource.com/c/sdk/+/196840
Change-Id: I1dd59d813172ac68ffcb189fcf3904c844828773
Reviewed-on: https://dart-review.googlesource.com/c/sdk/+/251960
Reviewed-by: Nicholas Shahan <nshahan@google.com>
When launched as a snapshot, the initial compile is slower than the existing pub approach because of a process start time of around 500 ms. When launched as a compiled executable, initial compile times are the same as the existing pub approach. Once launched, experimental results show times to produce a kernel file of at worst 1.5-2x faster than pub's solution and at best 10x faster than pub's solution. The typical workflow of making changes and recompiling results in an average of a 5x speedup with respect to pub's implementation.
Because compiler instances use a lot of memory, there is a limit on the number of active compilers that the resident server will keep alive, and will actively bring instances down when this limit is exceeded. If the user was previously compiling a given project during the lifespan of a ResidentFrontendServer and its compiler is taken down between requests, a new compiler instance will be allocated for the request. Performance is still between 1.5x-5x faster for this case when compared to pub's compile times.
Change-Id: If9ee1ecc71d660d34faf23381c764dc11d6a5902
Reviewed-on: https://dart-review.googlesource.com/c/sdk/+/252001
Reviewed-by: Siva Annamalai <asiva@google.com>
Reviewed-by: Jake Macdonald <jakemac@google.com>
Commit-Queue: Michael Richards <msrichards@google.com>
Reviewed-by: Alexander Aprelev <aam@google.com>
The WebSQL standard was abandoned more than 10 years ago and is not
supported by many browsers.
The `dart:web_sql` library was marked as deprecated in Dart 2.14. This
CL makes the library inaccesible, removes support for `dart:web_sql` imports,
and removes the `Window.openDatabase` API. The old code for `dart:web_sql` is
still generated by the html generators. Removing that will be handled by a
separate change.
Closes https://github.com/dart-lang/sdk/issues/46316
Change-Id: I892107396b3b227b4f33344377585aa5e5328288
Bug: https://github.com/dart-lang/sdk/issues/46316
Reviewed-on: https://dart-review.googlesource.com/c/sdk/+/216080
Reviewed-by: Srujan Gaddam <srujzs@google.com>
Commit-Queue: Sigmund Cherem <sigmund@google.com>
- Move expression evaluation to ddc in preparation for google3
- Added server to ddc to handle update and compileExpression requests
- Added tests
- Added 'experimental-output-compiled-kernel' option to ddc to generate
full kernel files only for compiled libraries, and store with
'.full.dill' extension
- Added AssetFileSystem to communicate to the asset server in the
debugger
- Made expression_compiler_worker work with full kernel files,
so removed invalidation of current file to improve performance
- Made expression_compiler_worker reuse already loaded imports
to avoid reading them from source in the incremental compiler
- Updated tests to work with DDC (for simulating webdev)
- Disabled tests that work with bazel kernel worker for now
as it does not generate full dill files yet
- Addressed code review comments from the prototype version:
https://dart-review.googlesource.com/c/sdk/+/157005
Details:
Currently, in flutter tools, expression evaluation is supported via
expression compilation, which is done by the incremental compiler in
the frontend server. The same incremental compiler is used for initial
application compilation, incremental code compilation for hot reload,
and any number of expression compilation requests.
In google3, the apps are typically too large to be compiled as a whole
in memory by the frontend server. Build in google3 is currently done by
blaze, as a distributed build using a task dependency graph. Build tasks
output kernel outline files as an interface between components produced
by individual tasks.
We are proposing an implementation of the expression compilation in
google3 that is taking advantage of full kernel files produced by the
build (supporting build changes to follow). This change introduces a
small server based on dev_compiler, which can handle following requests:
- update: load full kernel for given modules (done on app start)
- compileExpression: compile expression in a given library and module
(done when paused on a breakpoint)
Expression compilation uses previously loaded kernel files for the
application component and its dependencies to compile an expression.
Change-Id: Icf73868069faf3a2eb6d43ba78e459f8457e9e35
Reviewed-on: https://dart-review.googlesource.com/c/sdk/+/160944
Reviewed-by: Nicholas Shahan <nshahan@google.com>
Reviewed-by: Gary Roumanis <grouma@google.com>
Reviewed-by: Jens Johansen <jensj@google.com>
Reviewed-by: Jake Macdonald <jakemac@google.com>
Commit-Queue: Anna Gringauze <annagrin@google.com>
During expression compilation, if the compiled expression is using
a type that was not used in the current function, the incremental
compiler and DDC produce code that refers to undefined types.
To fix that, discharge types created during expression compilation
and add their definitions at the beginning of the generated
function.
Added tests to validate the behavior.
Fixes: https://github.com/dart-lang/sdk/issues/41443
Change-Id: If3fdce85a50ab2590d107f3b9e8c19b4768fd482
Reviewed-on: https://dart-review.googlesource.com/c/sdk/+/148468
Reviewed-by: Nicholas Shahan <nshahan@google.com>
Commit-Queue: Anna Gringauze <annagrin@google.com>
- Remove collecting private fields from scope calculation
We only need to collect the fields from the evaluated
expression and they are already collected separately.
- Correct private fields calculation
Currently, library names are assumed to be the same as the module,
which creates redefinitions of library variable in produced Javascript
code, and exceptions in chrome for modules that contain more than one
library.
The actual fix will come from making DDC incremental by storing more
information, for now make a best effort to compute correct names for
library variables from the module data that expression compiler
receives from chrome. The following code will be produced to calculate
private symbols _pf1 (from lib1, module1) and _pf2
(from lib2 module1):
let lib1 = require('module1.dart').lib1;
let lib2 = require('module1.dart').lib2;
let _pf1 = dart.privateNames(lib1, '_pf1');
let _pf2 = dart.privateNames(lib2, '_pf2');
Note that this seems to work even if the current breakpoint is inside
the define statement for lib1, and the lib1 symbol is not exported
yet.
Closes: https://github.com/dart-lang/sdk/issues/40272
Closes: https://github.com/dart-lang/sdk/issues/41585
Change-Id: I141719d2d5d5c08dd3c0ef5f0406756dce5575ab
Reviewed-on: https://dart-review.googlesource.com/c/sdk/+/145307
Reviewed-by: Sigmund Cherem <sigmund@google.com>
Commit-Queue: Anna Gringauze <annagrin@google.com>
ExpressionCompiler currently translates offsets of scopes to line
numbers during the binary search in the library in order to find
the inner-most scope containing the line where debugger has stopped.
This results in many offset-to-line translations per evaluation request,
each translation also performing a binary search in Source.lineStarts
table.
To make scope lookup more efficient, this change uses Source.lineStarts
table to find the offset for the debugger stop once, and uses integer
offset comparisons instead in the scope binary search.
Closes: https://github.com/dart-lang/sdk/issues/40281
Change-Id: I72052b144d15acef684a5f8d29b40f6c5774b723
Reviewed-on: https://dart-review.googlesource.com/c/sdk/+/142461
Commit-Queue: Anna Gringauze <annagrin@google.com>
Reviewed-by: Sigmund Cherem <sigmund@google.com>
Reviewed-by: Johnni Winther <johnniwinther@google.com>
Module names and import module names generated by the frontend server
are currently breaking debugger's assumptions on module names. This
change fixes it to make debugger works with various compiler
configurations, such as build_runner, frontend server with dwds tests,
and unblocks flutter tools to continue debugger and frontend server
integration.
JavaScriptBundle
- Change module import names to module names instead of file paths,
omit leading '/' as it cannot be in a module name in requireJS
- Module name changes are hidden under "debugger-module-names" flag
to prevent breaking flutter tools.
FrontendServer
- Always call exit after listening to commands is finished,
otherwise process running frontend server does not exit on 'quit'
command.
- Call computeCanonicalNames after initial compilation to support
subsequent module importing in compileExpressioToJs calls
- Add error handling to usage of kernelToJs compilers
ExpressionCompiler
- Separate library variables from library fields for loading modules,
as they can be different, for example
```main = require('web/main.dart').web__main```
Closes https://github.com/dart-lang/sdk/issues/40832
Change-Id: Ic103c22932c7181ee325f239193d32361d057ed0
Reviewed-on: https://dart-review.googlesource.com/c/sdk/+/138010
Commit-Queue: Anna Gringauze <annagrin@google.com>
Reviewed-by: Jonah Williams <jonahwilliams@google.com>
Reviewed-by: Gary Roumanis <grouma@google.com>
Reviewed-by: Jake Macdonald <jakemac@google.com>
This is a reland of 344c584ec4
First attempt failed due to lack of implementation of the new
API from SDK in Flutter/engine that this change introduces.
Fixed by creating dummy implementation in flutter/engine:
https://github.com/flutter/engine/pull/16309
Original change's description:
> Implementation of evaluation to JS in frontend server
>
> - made ProgramCompiler somewhat incremental by letting the user
> set the current library and class
> - fixed a bug in procedure_builder where extension method wrappers
> did not have correct fileEndOffset set, which prevented finding
> dart scope at a line when extension methods are used
> - added new compileExpressionToJs API to frontend server and
> frontend compiler interface
> - added ExpressionCompier class that combines IncrementalCompiler
> and ProgramCompiler to compile expression at given dart location
> to JavaScript
> - in JavascriptBundle, set the module name for library tracking in
> JavaScript and saved program compilers to a table for incremental
> reuse in expression compiler
> - Exposed generator from IncrementalCompiler for use in
> ExpressionCompiler
> - added tests for expression compiler
> - added test for compileExpressionToJs API in frontend server tests
>
>
> Change-Id: Ic5e7829e07030b8ad044da7d35bcf27e9fba81c8
> Reviewed-on: https://dart-review.googlesource.com/c/sdk/+/132701
> Commit-Queue: Anna Gringauze <annagrin@google.com>
> Reviewed-by: Alexander Aprelev <aam@google.com>
> Reviewed-by: Sigmund Cherem <sigmund@google.com>
> Reviewed-by: Gary Roumanis <grouma@google.com>
> Reviewed-by: Jake Macdonald <jakemac@google.com>
> Reviewed-by: Johnni Winther <johnniwinther@google.com>
Change-Id: I56426d2b6d831b2f8d8c57d468d0b54833a0062e
Reviewed-on: https://dart-review.googlesource.com/c/sdk/+/134561
Commit-Queue: Anna Gringauze <annagrin@google.com>
Reviewed-by: Sigmund Cherem <sigmund@google.com>
- made ProgramCompiler somewhat incremental by letting the user set
the current library and class
- fixed a bug in procedure_builder where extension method wrappers
did not have correct fileEndOffset set, which prevented finding
dart scope at a line when extension methods are used
- added new compileExpressionToJs API to frontend server and
frontend compiler interface
- added ExpressionCompier class that combines IncrementalCompiler
and ProgramCompiler to compile expression at given dart location
to JavaScript
- in JavascriptBundle, set the module name for library tracking in
JavaScript and saved program compilers to a table for incremental
reuse in expression compiler
- Exposed generator from IncrementalCompiler for use in
ExpressionCompiler
- added tests for expression compiler
- added test for compileExpressionToJs API in frontend server tests
Change-Id: Ic5e7829e07030b8ad044da7d35bcf27e9fba81c8
Reviewed-on: https://dart-review.googlesource.com/c/sdk/+/132701
Commit-Queue: Anna Gringauze <annagrin@google.com>
Reviewed-by: Alexander Aprelev <aam@google.com>
Reviewed-by: Sigmund Cherem <sigmund@google.com>
Reviewed-by: Gary Roumanis <grouma@google.com>
Reviewed-by: Jake Macdonald <jakemac@google.com>
Reviewed-by: Johnni Winther <johnniwinther@google.com>
Converts `package:` import uris into `/packages/` modules.
Also renames the output modules to append `.lib.js` instead of just `.js`. This allows us to distinguish between modules and applications based on extension.
Updates DDC source map code to be able to convert absolute file uris in sources so that they are relative to the source map.
Bug: https://github.com/dart-lang/webdev/issues/865
Change-Id: I55d70aa3761f10cc8bd7e92f5b567478040660de
Reviewed-on: https://dart-review.googlesource.com/c/sdk/+/132300
Reviewed-by: Nicholas Shahan <nshahan@google.com>
Reviewed-by: Sigmund Cherem <sigmund@google.com>
Reviewed-by: Jonah Williams <jonahwilliams@google.com>
Commit-Queue: Jake Macdonald <jakemac@google.com>
Fixes#39074
DDC emits Dart code that can usually be called with the same semantics
as JS there is no guarantee that a function passed to JS and then
invoked successfully was wrapped with `allowInterop`. The wrapping is
always required in Dart2JS. To make DDC more strict, add interceptors
that check for the usage of `allowInterop`.
Whenever a JS interop function or setter is passed an argument which is
statically typed as a Function, but not wrapped with `allowInterop` at
the call site, wrap it with `assertInterop` which will check the
argument at call time and fail with a clear error if it was not wrapped.
Whenever a JS interop function is torn off, either at the top level or
from an instance, wrap it with a function that will also inject these
checks at runtime.
There are still holes where we can't catch the mistake:
- An argument which is statically dynamic and a Function at runtime
won't be caught.
- A Function which is stored in a collection won't be caught.
- A JS interop definition where a getter returns a Function which takes
a Function as an argument is not checked.
- A dynamic call through to javascript is not checked.
Changes:
- Refactor `_isJsLibrary` and add `isJsMember`, and `isAllowInterop`
utilities to determine what needs wrapping.
- Update `assertInterop` to give a more clear error when it fails, and
to ignore non function arguments.
- Add `tearoffInterop` to wrap a function an ensure that any function
typed arguments are wrapped.
- Inject `assertInterop` around Function arguments passed to JS methods.
- Inject `assertInterop` around Function arguments passed to static or
instance JS setters.
- Inject a runtime wrapper around static or instance Function tearoffs.
- Add a test covering all flavors of checks that are supported.
- Change the interop expando to an `Expando<dynamic>` in the NNBD SDK to work
around a stricter type check. https://github.com/dart-lang/sdk/issues/39971
Potential improvements:
If the `tearoffInterop` turns out to be too heavy, we could loosen it so
that we only wrap methods if any of their argument types are statically
declared to be a Function.
Change-Id: Ibc92df5b54e1a041b4102a07b8398b774b6bd1d2
Reviewed-on: https://dart-review.googlesource.com/c/sdk/+/128462
Commit-Queue: Nate Bosch <nbosch@google.com>
Reviewed-by: Vijay Menon <vsm@google.com>
Reviewed-by: Nicholas Shahan <nshahan@google.com>
Original change was broken by the fact that DDC expects all types marked as
native have all their superclasses marked as native when the super classes are
compiled.
In this case `MapMixin` from dart:collection was not being marked as native and
the only reason it was working before was that the library dependency enforced
the necessary order.
* Now `MapMixin` is explicitly marked as native.
* Added a test case to use some of the API on `window.localStorage` that is
inherited from the MapMixin class.
Change-Id: I1584bfb86179016ee12c2acc5cfbbe81d086841e
Reviewed-on: https://dart-review.googlesource.com/c/sdk/+/126906
Reviewed-by: Sigmund Cherem <sigmund@google.com>
Reviewed-by: Mark Zhou <markzipan@google.com>
Commit-Queue: Nicholas Shahan <nshahan@google.com>