Adds Lo-Fi fallback support for new Data Reduction Proxy protocol.

tools/chrome_proxy/webdriver/lite_page.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 common
 from common import TestDriver
 from common import IntegrationTest
 
 import time
 
@@ skipping 79 matching lines @@
         'document.body.scrollHeight')
       self.assertGreater(new_scroll_height, original_scroll_height)
 
       # Make sure there were more requests that were proxied.
       responses = test_driver.GetHTTPResponses(override_has_logs=True)
       self.assertNotEqual(0, len(responses))
       for response in responses:
         self.assertHasChromeProxyViaHeader(response)
         self.assertIn(response.status, [200, 204])
 
   # Lo-Fi fallback is not currently supported via the client. Check that

[megjablon, 2017/06/05 23:47:59]

Update this to "Lo-Fi fallback is not supported without the
DataReductionProxyDecidesTransform feature. Check that no Lo-Fi response is
received if a Lite Page is not served."

[dougarnett, 2017/06/06 16:49:47]

Done.

   # no Lo-Fi response is received if a Lite Page is not served.
-  def testLitePageFallback(self):
+  def testLitePageNoFallback(self):
     with TestDriver() as test_driver:
       test_driver.AddChromeArg('--enable-spdy-proxy-auth')
       test_driver.AddChromeArg('--force-fieldtrials='
                                'DataCompressionProxyLoFi/Enabled_Preview/')
       test_driver.AddChromeArg('--force-fieldtrial-params='
                                'DataCompressionProxyLoFi.Enabled_Preview:'
                                'effective_connection_type/4G')
       test_driver.AddChromeArg('--force-net-effective-connection-type=2g')
 
       test_driver.LoadURL('http://check.googlezip.net/lite-page-fallback')
@@ skipping 14 matching lines @@
         if not response.url.endswith('png'):
           continue
 
         # Lo-Fi fallback is not currently supported via the client. Check that
         # no Lo-Fi response is received.
         self.checkLoFiResponse(response, False)
 
       # Verify that a Lite Page was requested.
       self.assertEqual(1, lite_page_requests)
 
+  # Verifies Lo-Fi fallback via the page-policies server directive.
+  # Note: this test is for the CPAT protocol change in M-61.
+  def testLitePageFallbackViaPagePolicies(self):

[megjablon, 2017/06/05 23:47:59]

Please also add tests with DataReductionProxyDecidesTransform feature on for
forcing a lite page via the flag and for forcing Lo-Fi enabled with the flag

[dougarnett, 2017/06/06 16:49:46]

In different CL? I don't see how these tests would apply to this change. I have
several more integration tests that I want to add (some already coded) - pending
server support pushing out to prod (also force_empty_image is not yet
implemented by the server but initial test for it verifying client sends force
exp is in another CL).

[dougarnett, 2017/06/07 16:57:49]

I went ahead and added my integration tests here for getting lite page for slow
connection but not for fast connection with new feature on. These work now
against staging but not yet for prod server (as ECT checking change has not yet
pushed to prod - should by end of week). 

+    with TestDriver() as test_driver:
+      test_driver.AddChromeArg('--enable-spdy-proxy-auth')
+      test_driver.AddChromeArg('--enable-features='
+                               'DataReductionProxyDecidesTransform')
+      test_driver.AddChromeArg('--force-fieldtrial-params='
+                               'NetworkQualityEstimator.Enabled:'
+                               'force_effective_connection_type/Slow2G,'
+                               'DataCompressionProxyLoFi.Enabled_Preview:'
+                               'effective_connection_type/2G')
+      test_driver.AddChromeArg('--force-fieldtrials='
+                               'NetworkQualityEstimator/Enabled/'
+                               'DataCompressionProxyLoFi/Enabled_Preview')
+
+      test_driver.LoadURL('http://check.googlezip.net/lite-page-fallback')
+
+      lite_page_responses = 0
+      lofi_resource = 0
+      for response in test_driver.GetHTTPResponses():
+        self.assertEqual('Slow-2G',
+                         response.request_headers['chrome-proxy-ect'])
+
+        if response.url.endswith('html'):
+          # Verify that the server provides the fallback directive
+          self.assertIn('page-policies=empty-image',
+                        response.response_headers['chrome-proxy'])
+          # Main resource should not accept and transform to lite page.
+          if self.checkLitePageResponse(response):
+            lite_page_responses = lite_page_responses + 1
+        if response.url.endswith('png'):
+          if self.checkLoFiResponse(response, True):
+            lofi_resource = lofi_resource + 1
+
+      self.assertEqual(0, lite_page_responses)
+      self.assertNotEqual(0, lofi_resource)
+
 if __name__ == '__main__':
   IntegrationTest.RunAllTests()