Add test to compare-failures

tools/gardening/lib/src/client.dart

Index: tools/gardening/lib/src/client.dart
diff --git a/tools/gardening/lib/src/client.dart b/tools/gardening/lib/src/client.dart
index 05eb1ad29f7a80be0fe57d1bbcb75dbba667793a..4358598d577f040118da8d497b2d652ce0e86465 100644
--- a/tools/gardening/lib/src/client.dart
+++ b/tools/gardening/lib/src/client.dart
@@ -28,7 +28,7 @@ class HttpBuildbotClient implements BuildbotClient {
 
   @override
   Future<BuildResult> readResult(BuildUri buildUri) {
-    return readBuildResult(_client, buildUri);
+    return readBuildResultFromHttp(_client, buildUri);
   }
 
   int get mostRecentBuildNumber => -2;
@@ -68,7 +68,7 @@ class LogdogBuildbotClient implements BuildbotClient {
     }
     while (true) {
       try {
-        return await readLogDogResult(buildUri);
+        return await readBuildResultFromLogDog(buildUri);
       } on LogdogException catch (e) {
         if (e.exitKind != LogdogExitKind.error) {
           return null;