Roll Dart SDK from b9c5118c73fd to 6bd220f55604 (15 revisions) (#20313)

DEPS

@@ -34,7 +34,7 @@ vars = {
   # Dart is: https://github.com/dart-lang/sdk/blob/master/DEPS.
   # You can use //tools/dart/create_updated_flutter_deps.py to produce
   # updated revision list of existing dependencies.
-  'dart_revision': 'b9c5118c73fda9a2e43e204ae52e375874bff9f0',
+  'dart_revision': '6bd220f5560427428588c6ab36b08d8aba6c9218',
 
   # WARNING: DO NOT EDIT MANUALLY
   # The lines between blank lines above and below are generated by a script. See create_updated_flutter_deps.py
@@ -180,13 +180,13 @@ deps = {
    Var('dart_git') + '/charcode.git@af1e2d59a9c383da94f99ea51dac4b93fb0626c4',
 
   'src/third_party/dart/third_party/pkg/cli_util':
-   Var('dart_git') + '/cli_util.git@0.1.4',
+   Var('dart_git') + '/cli_util.git@0.2.0',
 
   'src/third_party/dart/third_party/pkg/collection':
    Var('dart_git') + '/collection.git' + '@' + Var('dart_collection_rev'),
 
   'src/third_party/dart/third_party/pkg/convert':
-   Var('dart_git') + '/convert.git@49bde5b371eb5c2c8e721557cf762f17c75e49fc',
+   Var('dart_git') + '/convert.git@c1b01f832835d3d8a06b0b246a361c0eaab35d3c',
 
   'src/third_party/dart/third_party/pkg/crypto':
    Var('dart_git') + '/crypto.git@7422fb2f6584fe1839eb30bc4ca56e9f9760b801',

ci/licenses_golden/licenses_third_party

-Signature: a70112ca278316b38ab1368cc0e8cab0
+Signature: a0b54b64cb7d6856a321de38d031a65c
 
 UNUSED LICENSES:
 
@@ -8156,8 +8156,6 @@ FILE: ../../../third_party/dart/benchmarks/SoundSplayTreeSieve/dart/SoundSplayTr
 FILE: ../../../third_party/dart/benchmarks/SoundSplayTreeSieve/dart/sound_splay_tree.dart
 FILE: ../../../third_party/dart/benchmarks/SoundSplayTreeSieve/dart2/SoundSplayTreeSieve.dart
 FILE: ../../../third_party/dart/benchmarks/SoundSplayTreeSieve/dart2/sound_splay_tree.dart
-FILE: ../../../third_party/dart/runtime/bin/abi_version.h
-FILE: ../../../third_party/dart/runtime/bin/abi_version_in.cc
 FILE: ../../../third_party/dart/runtime/bin/elf_loader.cc
 FILE: ../../../third_party/dart/runtime/bin/elf_loader.h
 FILE: ../../../third_party/dart/runtime/bin/entrypoints_verification_test_extension.cc