If a file scheme and one or more roots is provided, fall back to this mapping before the direct file path if the file path cannot be turned into a package URI.

Use URI representation so that the transformation is resilient to the org-dartlang-app scheme used by the web builds.

Fixes #66095
Fixes #66404

* migrate some cupertino files to nullsafety

* address review comments

* address review comments

Wrapping the spacing SizedBox in Flexible.

This reverts commit af6ba867.

[flutter_tools] only lock if an upgrade/download will be performed (linux/macos) and output building messages to stderr (#65422)

Currently an invocation of flutter/dart will always attempt to acquire a lock. This can pose problems for tools that attempt to run multiple dart/flutter instances.

Instead update the lock logic (on Linux/macOS) so that we only attempt to acquire it if an update/snapshot needs to be performed. To avoid repeatedly performing downloads/snapshots if multiple flutter/dart invocations are fired off concurrently when an update needs to be performed, do a second check of the download/snapshot condition after the lock is released.

Additionally, moves all of the building/debug output to stderr on both the bash and batch scripts. This allows machine mode consumption of the tool to ignore needing to parse/handle the rebuild messages.

If a file scheme and one or more roots is provided, fall back to this mapping before the direct file path if the file path cannot be turned into a package URI.

Fixes #66095

Revert "Revert "Ensure VmService instance is disposed after failed direct connection attempt (#66123)" (#66164)" (#66377)

This reverts commit 3e6863ab.

This reverts commit 2be4570d.

This test is failing and was recently added.

SliverList perform layout start from the initial child when there is no valid layout offset (#66262)

Remove fake image implementations, add createTestImage to flutter_test

This reverts commit 5c858036.

This reverts commit 53fee1be.

This reverts commit 5c858036.

The k toggle allows switching between canvaskit and html backend at runtime. unfortunately this causes hot restart to break, since the dart_sdk modules stores state at runtime. The recommendation will be to use cavaskit via dart-defines.