This PR will update IntelliJ IDEA/Community validation logic for 2020.1 and later on Linux and Windows.

* 85b0031f7 Migration to PlatformDispatcher and multi-window (flutter/engine#20496)

* 0d151816c Remove uses of Dart VM bytecode mode from Flutter engine (flutter/engine#21741)

* 8be6cc039 Roll Skia from 88cda17bbeb8 to 61003cde7688 (4 revisions) (flutter/engine#21744)

* a2046aeb6 Revert "fix On iOS, dialog titles are announced twice (#19826)" (flutter/engine#21714)

* 3bd695b18 Roll Skia from 61003cde7688 to 13fc260c7080 (1 revision) (flutter/engine#21746)

* ca250c972 Roll Fuchsia Mac SDK from lqn8xmlDn... to gzhbqRUap... (flutter/engine#21749)

* 7f0e17b67 Roll Skia from 13fc260c7080 to aa64c352b349 (1 revision) (flutter/engine#21752)

* d97e74c7c Roll Fuchsia Linux SDK from EBX49sN_X... to YRTc9YoiB... (flutter/engine#21753)

* 7fc1a0386 Roll Skia from aa64c352b349 to d71dc2d25b8b (1 revision) (flutter/engine#21758)

* a3f3f989a Roll Fuchsia Mac SDK from gzhbqRUap... to _0R2HD4c8... (flutter/engine#21759)

* d4b8d676f Roll Fuchsia Linux SDK from YRTc9YoiB... to Nw5-0_sVF... (flutter/engine#21760)

* 910ce92e6 Roll Fuchsia Mac SDK from _0R2HD4c8... to 82ankF-Ht... (flutter/engine#21762)

* bd03014c2 Roll Fuchsia Mac SDK from 82ankF-Ht... to FFpTJfmj1... (flutter/engine#21768)

* f230fded7 Use buildroot clang for scenario app (flutter/engine#21690)

* 766d68282 Roll Fuchsia Linux SDK from Nw5-0_sVF... to h-DeV4tgE... (flutter/engine#21771)

* cff4ee74a Roll Skia from d71dc2d25b8b to ceb6214a556a (5 revisions) (flutter/engine#21772)

* fd1ba9ccf Ignore analysis warning for doc comment (flutter/engine#21773)

* 978cfd6d5 Roll Skia from ceb6214a556a to 9213e610ed92 (8 revisions) (flutter/engine#21774)

* 106842989 Roll Dart SDK from 06536d68ca0f to e256855d07ba (6 revisions) (flutter/engine#21775)

* 190fd8eb5 Reland "Create root isolate asynchronously (#20142)" (flutter/engine#21747)

* 10ed56318 Roll Skia from 9213e610ed92 to 840e8ea7403e (11 revisions) (flutter/engine#21779)

* e18cd9687 Roll Skia from 840e8ea7403e to ab6e62c131e9 (7 revisions) (flutter/engine#21783)

* 931a04683 Fix documentation build for window changes. (flutter/engine#21780)

* 38d8ebaa4 E2e screenshot tests2 (flutter/engine#21383)

* d912d502d [null-safety] fix build rule to produce sound dill (flutter/engine#21784)

* 05d97932b Extract a TextRange class for selection (flutter/engine#21722)

* c2938d06b Revert "Migration to PlatformDispatcher and multi-window #20496" (flutter/engine#21792)

All of the network requests from google cloud storage include an x-goog-hash header which contains an MD5 checksum. If present, use to validate that the downloaded binary is valid. This will rule out corrupt files as the cause of getting started crashers in the flutter_tool.

#38980

This does not fully resolve the above issue, because while we can check if the checksum matches what was expected from cloud storage, this A) may not necessarily be present and B) may not match up to what should be uploaded as part of the engine build process.

But when life gives you lemons you hash those lemons using an outdated hashing algorithm.

A change which sped up hot restart locally caused many of the devicelab measures to regress. I think this is because we do not measure when the isolate is actually "ready", so starting a reload or restart prematurely can cause time spent doing initialization to be registered as part of the reload operation.

A fix for this would be to have the framework include some sort of "initialization complete" event ... but it is not clear what the correct trigger would be. Perhaps after the first frame is successfully registered?

(9a3a0dc1 caused the benchmark regression - possibly since we spend less time syncing files now so we start the restart earlier)

Migrates the following files to NNBD: 
* input_decorator_test.dart
* list_tile_test.dart
* localizations_test.dart
* material_button_test.dart
* material_state_property_test.dart
* material_test.dart
* mergeable_material_test.dart

* Expose date symbols and patterns for en_US in framework

This reverts commit da58f5e6.

Revert "[flutter_tools] reland: fold process resolution logic into the flutter tool (#67957)" (#67968)

This reverts commit bd813879.

According to https://dart.dev/tools/pub/pubspec#name , uppercase is not permitted for package names.

Reland of #67669

The flutter tool has a number of crashes on stable where an ArgumentError is thrown due to the process manager not being able to resolve an executable.

So that we can adjust/modify this logic, fold it into flutter and add some additional logging.
caches the resolved executable per target directory, to avoid repeated look ups.
Instead of throwing an argument error, attempts to run the executable as given if an exact path can't be found
Accept files or symlinks for the executable path.
user where/which to resolve path instead of package:process logic.

Exposes contentPadding property for RadioListTile from its appropriate ListTile.

On every hot reload, the flutter tool must file stat each asset in the bundle. With a large number of assets or a slow file system, this can take 20 - 30 ms. Do this operation while the flutter tool is waiting for a response from the frontend_server.

No tests updated since this is only a timing update. Any difference in behavior will be shown on benchmarks

This reverts commit 10c78c26.

The flutter tool has a number of crashes on stable where an ArgumentError is thrown due to the process manager not being able to resolve an executable. Fold the resolution logic into the tool and use where/which instead of the package:process specific logic.

Fixes #61772

tool exit if there is no file at the path provided when building/running with sksl

Work towards #39925

Currently flutter run will uninstall and reinstall if the initial install fails and the APK was previously installed. Allow drive to share this same logic by moving it into installApp and out of startApp.

This should reduce the occurrence of the error in the devicelab.

This failure has been happening for a while but was covered by the overly broad catch. Removing that revealed that newer intellij versions have a different plugins file. The tool still can't find the file, but it won't crash now

Fixes #67918

Just another nnbd conversion PR.

In case different powershell module is installed over the default name. Fixes #22896

For historical reasons, the flutter tool uploads dill files to paths based on the entrypoint URI. This isn't actually necessary, and the tool can use specific files : main.dart.incremental.dill for incremental dills, and main.dart.dill/main.dart.swap.dill for full dills. This allows hot restarting applications with an entrypoint outside of lib/ and simplifies the devFS code.

Fixes #63243

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