Roll Dart to 8d4074175fb95cd4da810b4bf652a956449bac37 (#5089)

DEPS

@@ -31,7 +31,7 @@ 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': 'fe606f890b0a311da802c78b0af414a3c2087a79',
+  'dart_revision': '8d4074175fb95cd4da810b4bf652a956449bac37',
 
   'dart_args_tag': '1.4.1',
   'dart_async_tag': '2.0.6',
@@ -59,7 +59,7 @@ vars = {
   'dart_http_throttle_tag': '1.0.1',
   'dart_intl_tag': '0.15.2',
   'dart_json_rpc_2_tag': '2.0.6',
-  'dart_linter_tag': '0.1.47',
+  'dart_linter_tag': '0.1.49',
   'dart_logging_tag': '0.11.3+1',
   'dart_markdown_tag': '1.1.1',
   'dart_matcher_tag': '0.12.1+4',

tools/licenses/pubspec.lock

 # Generated by pub
-# See http://pub.dartlang.org/doc/glossary.html#lockfile
+# See https://www.dartlang.org/tools/pub/glossary#lockfile
 packages:
   archive:
     dependency: "direct main"
@@ -58,4 +58,4 @@ packages:
     source: hosted
     version: "1.1.5"
 sdks:
-  dart: ">=1.21.0 <=2.0.0-dev.20.0"
+  dart: ">=1.21.0 <=2.0.0-edge.c080951d45e79cd25df98036c4be835b284a269c"

travis/licenses_golden/licenses_third_party

-Signature: 78a7c160dd2a69a8ea38cb8bd839dadb
+Signature: 8833ca9e32a14087bf1856b68d4d3aaf
 
 UNUSED LICENSES:
 
@@ -4359,6 +4359,7 @@ FILE: ../../../third_party/dart/client/idea/.idea/inspectionProfiles/Project_Def
 FILE: ../../../third_party/dart/client/idea/.idea/vcs.xml
 FILE: ../../../third_party/dart/runtime/CPPLINT.cfg
 FILE: ../../../third_party/dart/runtime/observatory/.analysis_options
+FILE: ../../../third_party/dart/runtime/observatory/dart2js.packages
 FILE: ../../../third_party/dart/runtime/observatory/lib/elements.dart
 FILE: ../../../third_party/dart/runtime/observatory/lib/src/elements/img/chromium_icon.png
 FILE: ../../../third_party/dart/runtime/observatory/lib/src/elements/img/dart_icon.png