Quote all arguments when printing a Command

tools/testing/dart/test_runner.dart

Index: tools/testing/dart/test_runner.dart
diff --git a/tools/testing/dart/test_runner.dart b/tools/testing/dart/test_runner.dart
index 4d879e49f72695533433092b3ceeaab18df63037..262440fa664efcd0cbc2549143566a86f192e0d1 100644
--- a/tools/testing/dart/test_runner.dart
+++ b/tools/testing/dart/test_runner.dart
@@ -107,7 +107,9 @@ class Command {
       // TODO(efortuna): Remove this when fixed (Issue 1306).
       executable = executable.replaceAll('/', '\\');
     }
-    commandLine = "$executable ${arguments.join(' ')}";
+    var quotedArguments = [];
+    arguments.forEach((argument) => quotedArguments.add('"$argument"'));
+    commandLine = "$executable ${quotedArguments.join(' ')}";
   }
 
   String toString() => commandLine;
@@ -303,10 +305,6 @@ class TestCase {
         newArguments.addAll(c.arguments);
         final newCommand = new Command(newExecutablePath, newArguments);
         newCommands.add(newCommand);
-        // If there are extra spaces inside the prefix or suffix, this fails.
-        String expected =
-            '$prefix ${c.executable} $suffix ${c.arguments.join(' ')}';
-        Expect.stringEquals(expected.trim(), newCommand.commandLine);
       }
       commands = newCommands;
     }
@@ -1606,7 +1604,7 @@ class ProcessQueue {
           i++;
         }
         for (Command command in test.commands) {
-          print('$i. ${command.commandLine}');
+          print('$i. $command');
           i++;
         }
       }