Revert "[Test] Remove some dead code."

This reverts commit dc31c4631c499647f0855cd5d1c84aeaf501781b.

Reason for revert: <INSERT REASONING HERE>

Original change's description:
> [Test] Remove some dead code.
> 
> Change-Id: I619a06fecce3d006ab573163a33e01f70d6af9d5
> Reviewed-on: https://dart-review.googlesource.com/c/sdk/+/103180
> Reviewed-by: Ryan Macnak <rmacnak@google.com>
> Commit-Queue: Siva Annamalai <asiva@google.com>

TBR=rmacnak@google.com,asiva@google.com

# Not skipping CQ checks because original CL landed > 1 day ago.

Change-Id: I58847ca7612f12a64c6add78af4073eb2dfa7563
Reviewed-on: https://dart-review.googlesource.com/c/sdk/+/103404
Reviewed-by: Siva Annamalai <asiva@google.com>
diff --git a/tools/testing/dart/compiler_configuration.dart b/tools/testing/dart/compiler_configuration.dart
index 7c55c86..ca2437b 100644
--- a/tools/testing/dart/compiler_configuration.dart
+++ b/tools/testing/dart/compiler_configuration.dart
@@ -188,6 +188,11 @@
       List<String> originalArguments,
       CommandArtifact artifact) {
     var args = <String>[];
+    if (_isDebug) {
+      // Temporarily disable background compilation to avoid flaky crashes
+      // (see http://dartbug.com/30016 for details).
+      args.add('--no-background-compilation');
+    }
     if (_useEnableAsserts) {
       args.add('--enable_asserts');
     }