telemetry: Add tough scheduling cases

tools/telemetry/telemetry/page/actions/synthetic_delay.py

+# Copyright (c) 2012 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.
+from telemetry.page.actions import page_action

[nduca, 2013/11/24 19:22:46]

lets put a docstring on this class that explains what it does

[Sami, 2013/11/29 19:29:17]

Done.

+
+class SyntheticDelayAction(page_action.PageAction):
+  def __init__(self, attributes=None):
+    super(SyntheticDelayAction, self).__init__(attributes)
+
+  def WillRunAction(self, page, tab):
+    # Fail if browser doesn't support synthetic delays.
+    if not tab.EvaluateJavaScript("""
+        !!(window.chrome &&
+           chrome.gpuBenchmarking &&
+           chrome.gpuBenchmarking.configureSyntheticDelay);"""):
+      raise page_action.PageActionNotSupported(
+          'Synthetic delays not supported for this browser')
+
+  def RunAction(self, page, tab, previous_action):
+    done_callback = 'function() { window.__syntheticDelayActionDone = true; }'
+    target_duration = float(getattr(self, 'target_duration', '0'))
+    mode = getattr(self, 'mode', 'static')
+    tab.ExecuteJavaScript("""
+        window.__syntheticDelayActionDone = false;
+        chrome.gpuBenchmarking.configureSyntheticDelay("%s", %f, "%s", %s);"""
+        % (self.name, target_duration, mode, done_callback))
+    tab.WaitForJavaScriptExpression('window.__syntheticDelayActionDone ', 10)
+
+  def CustomizeBrowserOptions(self, options):
+    options.AppendExtraBrowserArgs('--enable-gpu-benchmarking')