Add BuildBotClient to abstract http/logdog access

tools/gardening/lib/src/util.dart

Index: tools/gardening/lib/src/util.dart
diff --git a/tools/gardening/lib/src/util.dart b/tools/gardening/lib/src/util.dart
index 66f986944367fe9fb7bfb4fbf7565bca703e2c0c..6d82076694aa4113dc89eb0137dd68c92c6793c5 100644
--- a/tools/gardening/lib/src/util.dart
+++ b/tools/gardening/lib/src/util.dart
@@ -51,12 +51,15 @@ Future<String> readUriAsText(HttpClient client, Uri uri) async {
 }
 
 ArgParser createArgParser() {
-  ArgParser argParser = new ArgParser();
+  ArgParser argParser = new ArgParser(allowTrailingOptions: true);
   argParser.addFlag('verbose',
       abbr: 'v', negatable: false, help: "Turn on logging output.");
+  argParser.addFlag('no-cache', help: "Disable caching.");
   argParser.addOption('cache',
       help: "Use <dir> for caching test output.\n"
           "Defaults to 'temp/gardening-cache/'.");
+  argParser.addFlag('logdog',
+      negatable: false, help: "Pull test results from logdog.");
   return argParser;
 }
 
@@ -67,4 +70,7 @@ void processArgResults(ArgResults argResults) {
   if (argResults['cache'] != null) {
     cache.base = Uri.base.resolve('${argResults['cache']}/');
   }
+  if (argResults['no-cache']) {
+    cache.base = null;
+  }
 }