Add video metrics integration test

tools/chrome_proxy/webdriver/video.py

 # Copyright 2017 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 time
 
 import common
 from common import TestDriver
 from common import IntegrationTest
 
@@ skipping 24 matching lines @@
       )
       saw_video_response = False
       for response in t.GetHTTPResponses():
         if 'video' in response.response_headers['content-type']:
           self.assertNotHasChromeProxyViaHeader(response)
           saw_video_response = True
         else:
           self.assertHasChromeProxyViaHeader(response)
       self.assertTrue(saw_video_response, 'No video request seen in test!')
 
+  # Check the compressed video has the same frame count, width, height, and
+  # duration as uncompressed.
+  def testVideoMetrics(self):
+    expected = {
+      'duration': 60.127,
+      'webkitDecodedFrameCount': 1080.0,
+      'videoWidth': 640.0,
+      'videoHeight': 360.0
+    }
+    with TestDriver() as t:
+      t.AddChromeArg('--enable-spdy-proxy-auth')
+      t.LoadURL('http://check.googlezip.net/cacheable/video/buck_bunny_640x360_24fps_video.html')
+      # Check request vwas proxied and we got a compressed video back.
+      for response in t.GetHTTPResponses():
+        self.assertHasChromeProxyViaHeader(response)
+        if ('content-type' in response.response_headers
+            and 'video' in response.response_headers['content-type']):
+          self.assertEqual('video/webm',
+            response.response_headers['content-type'])
+      t.ExecuteJavascriptStatement('document.getElementById("video").play()')
+      # Wait for the video to finish playing, plus some headroom.
+      time.sleep(80)

[RyanSturm, 2017/02/17 19:24:10]

What is the impact of having a test that takes 80 seconds to run (impact on the
continuous test harness)? I know if you add this test, I will end up never
running all the integration tests because this one takes too long to run. I have
no suggestions on how to fix it if the test truly needs to watch the whole
video.

[Robert Ogden, 2017/02/17 19:28:18]

The test harness itself it happy to wait, but yes it'll make the whole test
suite a rather long event. This test has to play all the way through because I
don't have another way to ensure chrome decodes all the frames. Besides, so far
all the tests in this class save the XHR one wait through the entire video :/

[Tom Bergan, 2017/02/17 20:10:56]

We should be able to use a shorter video. No reason the video needs to be 60s.

+bolian
+harringtond

[bolian, 2017/02/17 20:21:57]

I am not sure how the test works internally. At least Chrome seems to know all
the duration, width, height, etc as long as the video starts playing. So, do you
need to wait for it to finish playing?

If that is not possible, adding a much shorter video sounds good to me.

+      # Check each metric against its expected value.
+      for metric in expected:
+        actual = float(t.ExecuteJavascriptStatement(
+          'document.getElementById("video").%s' % metric))
+        self.assertAlmostEqual(expected[metric], actual, msg="Compressed video "
+          "metric doesn't match expected! Metric=%s Expected=%f Actual=%f"
+          % (metric, expected[metric], actual), places=None, delta=0.25)
+
   # Check the frames of a compressed video.
   def testVideoFrames(self):
     self.instrumentedVideoTest('http://check.googlezip.net/cacheable/video/buck_bunny_640x360_24fps_video.html')
 
   # Check the audio volume of a compressed video.
   def testVideoAudio(self):
     self.instrumentedVideoTest('http://check.googlezip.net/cacheable/video/buck_bunny_640x360_24fps_audio.html')
 
   def instrumentedVideoTest(self, url):
     """Run an instrumented video test. The given page is reloaded up to some
@@ skipping 26 matching lines @@
       wait_time = int(t.ExecuteJavascriptStatement('test.waitTime'))
       t.WaitForJavascriptExpression('test.metrics.complete', wait_time)
       metrics = t.ExecuteJavascriptStatement('test.metrics')
       if not metrics['complete']:
         raise Exception('Test not complete after %d seconds.' % wait_time)
       if metrics['failed']:
         raise Exception('Test failed!')
 
 if __name__ == '__main__':
   IntegrationTest.RunAllTests()