Added ability to disable logging in mocks, to avoid the memory overhead if you don't need behavior …

lib/unittest/unittest.dart

Index: lib/unittest/unittest.dart
===================================================================
--- lib/unittest/unittest.dart	(revision 9562)
+++ lib/unittest/unittest.dart	(working copy)
@@ -360,7 +360,7 @@
     // Always run except if the test is done.
     if (_testCase.isComplete) {
       _testCase.error(
-          'Callback called after already being marked as done ($_calls)',
+          'Callback called after already being marked as done ($_calls).',
           '');
       _state = _UNCAUGHT_ERROR;
       return false;
@@ -387,7 +387,8 @@
         return _callback(arg0, arg1, arg2, arg3);
       } else {
         _testCase.error(
-           'unittest lib does not support callbacks with more than 4 arguments',
+           'unittest lib does not support callbacks with more than'
+              ' 4 arguments.',
            '');
         _state = _UNCAUGHT_ERROR;
       }
@@ -433,7 +434,7 @@
     if (_calls > _expectedCalls) {
       _testCase.error(
           'Callback called more times than expected '
-             '($_calls > $_expectedCalls)',
+             '($_calls > $_expectedCalls).',
           '');
       _state = _UNCAUGHT_ERROR;
       return false;
@@ -592,7 +593,7 @@
         final expected = testCase.callbacks;
         testCase.error(
             'More calls to _handleAllCallbacksDone() than expected. '
-            'Actual: ${_callbacksCalled}, expected: ${expected}', '');
+            'Actual: ${_callbacksCalled}, expected: ${expected}.', '');
         _state = _UNCAUGHT_ERROR;
       } else if ((_callbacksCalled == testCase.callbacks) &&
           (_state != _RUNNING_TEST)) {