Refactor the way that TestApi works so that it is actually useful.

scripts/slave/recipe_modules/json/test_api.py

+from slave import recipe_test_api
+
+from .util import TestResults
+
+class JsonTestApi(recipe_test_api.RecipeTestApi):
+  @recipe_test_api.placeholder_step_data
+  @staticmethod
+  def output(data, retcode=None):
+    return data, retcode
+
+  @recipe_test_api.placeholder_step_data
+  @staticmethod
+  def test_results(test_results, retcode=None):
+    return test_results.as_jsonish(), retcode
+
+  def canned_test_output(self, good, passes=9001):
+    """Produces a 'json test results' compatible object with some canned tests.
+    Args:
+      good - Determines if this test result is passing or not.
+      passes - The number of (theoretically) passing tests.
+    """
+    bad = lambda fail_val: None if good else fail_val
+    t = TestResults()
+    t.raw['num_passes'] = passes
+    t.add_result('good/totally-awesome.html', 'PASS')
+    t.add_result('flake/totally-flakey.html', 'PASS', bad('TIMEOUT PASS'))
+    t.add_result('tricky/totally-maybe-not-awesome.html', 'PASS', bad('FAIL'))
+    t.add_result('bad/totally-bad-probably.html', 'PASS', bad('FAIL'))
+    ret = self.test_results(t)
+    ret.retcode = 0 if good else 1
+    return ret