Enable browser testing on CI, fix one test with browser-specific issues (dart-lang/stack_trace#120)

pkgs/stack_trace/.github/workflows/test-package.yml

diff --git a/pkgs/stack_trace/.github/workflows/test-package.yml b/pkgs/stack_trace/.github/workflows/test-package.yml
index 1b823da..23916f3 100644
--- a/pkgs/stack_trace/.github/workflows/test-package.yml
+++ b/pkgs/stack_trace/.github/workflows/test-package.yml
@@ -59,3 +59,6 @@
       - name: Run VM tests
         run: dart test --platform vm
         if: always() && steps.install.outcome == 'success'
+      - name: Run browser tests
+        run: dart test --platform chrome
+        if: always() && steps.install.outcome == 'success'

pkgs/stack_trace/test/chain/chain_test.dart

diff --git a/pkgs/stack_trace/test/chain/chain_test.dart b/pkgs/stack_trace/test/chain/chain_test.dart
index 6de759b..aa4256b 100644
--- a/pkgs/stack_trace/test/chain/chain_test.dart
+++ b/pkgs/stack_trace/test/chain/chain_test.dart
@@ -48,8 +48,13 @@
       expect(chain.traces[0].frames[0].toString(),
           equals('package:my_lib.dart 134:5 in MyClass.run'));
       expect(chain.traces[1].frames, hasLength(1));
-      expect(chain.traces[1].frames[0].toString(),
-          equals('/my_app.dart 9:3 in main'));
+      expect(
+        chain.traces[1].frames[0].toString(),
+        anyOf(
+          equals('/my_app.dart 9:3 in main'), // VM
+          equals('file:///my_app.dart 9:3 in main'), // Browser
+        ),
+      );
     });
   });