Remove a stale comment (#1609)

The comment was intended to clarify the side effect of returning null.
The null return was refactored to a call to `engine.pause()` which has a
name that conveys the meaning of the comment.
diff --git a/pkgs/test/CHANGELOG.md b/pkgs/test/CHANGELOG.md
index 6753d5b..cc31f0a 100644
--- a/pkgs/test/CHANGELOG.md
+++ b/pkgs/test/CHANGELOG.md
@@ -1,3 +1,5 @@
+## 1.19.2-dev
+
 ## 1.19.1
 
 * Fix parsing of file paths into a URI on windows.
diff --git a/pkgs/test/pubspec.yaml b/pkgs/test/pubspec.yaml
index cb7496f..41ce08e 100644
--- a/pkgs/test/pubspec.yaml
+++ b/pkgs/test/pubspec.yaml
@@ -1,5 +1,5 @@
 name: test
-version: 1.19.1
+version: 1.19.2-dev
 description: >-
   A full featured library for writing and running Dart tests across platforms.
 repository: https://github.com/dart-lang/test/blob/master/pkgs/test
@@ -33,7 +33,7 @@
   yaml: ^3.0.0
   # Use an exact version until the test_api and test_core package are stable.
   test_api: 0.4.6
-  test_core: 0.4.7
+  test_core: 0.4.8
 
 dev_dependencies:
   fake_async: ^1.0.0
diff --git a/pkgs/test_core/CHANGELOG.md b/pkgs/test_core/CHANGELOG.md
index 1596b3a..f0f7bca 100644
--- a/pkgs/test_core/CHANGELOG.md
+++ b/pkgs/test_core/CHANGELOG.md
@@ -1,3 +1,5 @@
+## 0.4.8-dev
+
 ## 0.4.7
 
 * Fix parsing of file paths into a URI on windows.
diff --git a/pkgs/test_core/lib/src/runner/debugger.dart b/pkgs/test_core/lib/src/runner/debugger.dart
index 532aa68..f7638b1 100644
--- a/pkgs/test_core/lib/src/runner/debugger.dart
+++ b/pkgs/test_core/lib/src/runner/debugger.dart
@@ -29,8 +29,6 @@
   _Debugger? debugger;
   var canceled = false;
   return CancelableOperation.fromFuture(() async {
-    // Make the underlying suite null so that the engine doesn't start running
-    // it immediately.
     engine.suiteSink.add(loadSuite.changeSuite((runnerSuite) {
       engine.pause();
       return runnerSuite;
diff --git a/pkgs/test_core/pubspec.yaml b/pkgs/test_core/pubspec.yaml
index 66e4522..bc544fc 100644
--- a/pkgs/test_core/pubspec.yaml
+++ b/pkgs/test_core/pubspec.yaml
@@ -1,5 +1,5 @@
 name: test_core
-version: 0.4.7
+version: 0.4.8-dev
 description: A basic library for writing tests and running them on the VM.
 homepage: https://github.com/dart-lang/test/blob/master/pkgs/test_core