Migrate Telemetry from beginWindowSnapshotPNG to Page.captureScreenshot

content/test/gpu/gpu_tests/screenshot_sync.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 os
+import random
 
 import screenshot_sync_expectations as expectations
 
 from telemetry import test
 from telemetry.core import util
 from telemetry.page import page
 from telemetry.page import page_set
 from telemetry.page import page_test
 # pylint: disable=W0401,W0614
 from telemetry.page.actions.all_page_actions import *
 
 data_path = os.path.join(
     util.GetChromiumSrcDir(), 'content', 'test', 'data', 'gpu')
 
 class _ScreenshotSyncValidator(page_test.PageTest):
-  def CustomizeBrowserOptions(self, options):
-    options.AppendExtraBrowserArgs('--enable-gpu-benchmarking')
+  def ValidatePage(self, page, tab, results):
+    if not tab.screenshot_supported:
+      raise page_test.Failure('Browser does not support screenshot capture')
 
-  def ValidatePage(self, page, tab, results):
-    test_success = tab.EvaluateJavaScript('window.__testSuccess')
-    if not test_success:
-      message = tab.EvaluateJavaScript('window.__testMessage')
-      raise page_test.Failure(message)
+    def CheckColorMatch(canvasRGB, screenshotRGB):
+      for i in range(0, 3):
+        if abs(canvasRGB[i] - screenshotRGB[i]) > 1:
+          raise page_test.Failure('Color mismatch in component #%d: %d vs %d' %
+              (i, canvasRGB[i], screenshotRGB[i]))
+
+    def CheckScreenshot():
+      canvasRGB = [];
+      for i in range(0, 3):
+        canvasRGB.append(random.randint(0, 255))
+      tab.EvaluateJavaScript("window.draw(%d, %d, %d);" % tuple(canvasRGB))
+      screenshot = tab.Screenshot(5)
+      CheckColorMatch(canvasRGB, screenshot.pixels)
+
+    repetitions = 50
+    for n in range(0, repetitions):
+      CheckScreenshot()
 
 
 class ScreenshotSyncPage(page.Page):
   def __init__(self, page_set, base_dir):
     super(ScreenshotSyncPage, self).__init__(
       url='file://screenshot_sync.html',
       page_set=page_set,
       base_dir=base_dir,
       name='ScreenshotSync')
     self.user_agent_type = 'desktop'
 
   def RunNavigateSteps(self, action_runner):
     action_runner.NavigateToPage(self)
-    action_runner.RunAction(WaitAction({
-      'javascript': 'window.__testComplete',
-      'timeout': 120}))
 
 
 class ScreenshotSyncProcess(test.Test):
   """Tests that screenhots are properly synchronized with the frame one which
   they were requested"""
   test = _ScreenshotSyncValidator
 
   def CreateExpectations(self, page_set):
     return expectations.ScreenshotSyncExpectations()
 
   def CreatePageSet(self, options):
     ps = page_set.PageSet(
       file_path=data_path,
       description='Test cases for screenshot synchronization',
       serving_dirs=[''])
     ps.AddPage(ScreenshotSyncPage(ps, ps.base_dir))
     return ps