* Remove use_modular_headers from Podfiles using libraries

* Remove @imports

This fixes a breakage in fuchsia where package_config version 1.1.0 is
required but flutter_tools is currently locked to 1.05.

* Moved the default BinaryMessenger instance to ServicesBinding

This reverts commit 821602ae.

* Added assertion in defaultBinaryMessenger. Also fixed the devicelab tests.

This reverts commit 92ef2b9c.

This requires either runApp() or
WidgetsFlutterBinding.ensureInitialized() to have been called before
using any MethodChannels. Plugins broadly rely on MethodChannels and
right now there's no general requirements that they be constructed
within the runApp call, so the ecosystem breakages from this are broader
than originally thought. Reverting for now.

If xcode_backend.sh script fails or substitute variables are missing, fail the host Xcode build (#37449)

Disable CocoaPods input and output paths in Xcode build phase and adopt new Xcode build system (#34167)

Updates the Podfile template to use the CocoaPod disable_input_output_paths installation option which prevents the [CP] Embed Pods Frameworks build phase from outputting the Flutter.framework files.

Revert "Disable CocoaPods input and output paths in Xcode build phase and adopt new Xcode build system (#33852)" (#33882)

This reverts commit d053fe5c.

Disable CocoaPods input and output paths in Xcode build phase and adopt new Xcode build system (#33852)

Updates the Podfile template to use the CocoaPod disable_input_output_paths installation option which prevents the [CP] Embed Pods Frameworks build phase from outputting the Flutter.framework files.

Revert "Disable CocoaPods input and output paths in Xcode build phase and adopt new Xcode build system (#33684)"

This reverts commit ef792fc3.

Disable CocoaPods input and output paths in Xcode build phase and adopt new Xcode build system (#33684)

Updates the Podfile template to use the CocoaPod disable_input_output_paths installation option which prevents the [CP] Embed Pods Frameworks build phase from outputting the Flutter.framework files.

This relands flutter/flutter#33163 with a fix to the integration_ui test.

This reverts commit 52ae9968.

* Clean up some flutter_tools tests

* Remove arbitrary retry that happens even for fundamental errors, and generally clean up _DevFSHttpWriter.

* Update dependencies (requires fixes; see next commit)

* Fixes for new dependencies.

* Updating dart.dev related links

* Update packages/flutter_tools/lib/src/base/context.dart