telemetry: Use trace categories to configure synthetic delays

tools/perf/metrics/smoothness_unittest.py

+# Copyright 2014 The Chromium Authors. All rights reserved.
+# Use of this source code is governed by a BSD-style license that can be
+# found in the LICENSE file.
+
+import unittest
+
+from metrics import smoothness
+
+from telemetry.page import page
+
+
+class FakePlatform(object):
+  def IsRawDisplayFrameRateSupported(self):
+    return False
+
+
+class FakeBrowser(object):
+  def __init__(self):
+    self.platform = FakePlatform()
+    self.category_filter = None
+
+  def StartTracing(self, category_filter, _):
+    self.category_filter = category_filter
+
+
+class FakeTab(object):
+  def __init__(self):
+    self.browser = FakeBrowser()
+
+  def ExecuteJavaScript(self, js):
+    pass
+
+
+class SmoothnessMetricUnitTest(unittest.TestCase):
+  def testSyntheticDelayConfiguration(self):
+    attributes = {
+      'synthetic_delays': {
+        'cc.BeginMainFrame': { 'target_duration': 0.012 },
+        'cc.DrawAndSwap': { 'target_duration': 0.012, 'mode': 'alternating' },
+        'gpu.SwapBuffers': { 'target_duration': 0.012 }
+      }
+    }
+    test_page = page.Page('http://dummy', None, attributes=attributes)
+
+    tab = FakeTab()
+    smoothness_metric = smoothness.SmoothnessMetric()
+    smoothness_metric.Start(test_page, tab)
+
+    expected_category_filter = [
+        'DELAY(cc.BeginMainFrame;0.012000;static)',
+        'DELAY(cc.DrawAndSwap;0.012000;alternating)',
+        'DELAY(gpu.SwapBuffers;0.012000;static)',
+        'benchmark',
+        'webkit.console'
+    ]
+    self.assertEquals(expected_category_filter,
+                      sorted(tab.browser.category_filter.split(',')))