Implement the LitePage Integration Test with ChromeDriver

tools/chrome_proxy/webdriver/lofi.py

Index: tools/chrome_proxy/webdriver/lofi.py
diff --git a/tools/chrome_proxy/webdriver/lofi.py b/tools/chrome_proxy/webdriver/lofi.py
index 3fbfb0159205416df26f256bf0542be22ca337f1..9d6ca72a6b0524476d6d6a098d96ae47c7b1a2d4 100644
--- a/tools/chrome_proxy/webdriver/lofi.py
+++ b/tools/chrome_proxy/webdriver/lofi.py
@@ -42,5 +42,36 @@ class Bypass(IntegrationTest):
       # Verify that Lo-Fi responses were seen.
       self.assertNotEqual(0, lofi_responses)
 
+  # Checks that a Lite Page is served and that the ignore_preview_blacklist
+  # experiment is being used.
+  def testLitePage(self):
+    with TestDriver() as test_driver:
+      test_driver.AddChromeArg('--enable-spdy-proxy-auth')
+      test_driver.AddChromeArg('--data-reduction-proxy-lo-fi=always-on')
+      test_driver.AddChromeArg('--enable-data-reduction-proxy-lite-page')
+      test_driver.AddChromeArg('--disable-quic')

[tbansal1, 2017/02/23 23:35:21]

Why disable quic?

[megjablon, 2017/02/23 23:47:52]

There was some reason you disabled it in the telemetry test. Not 100% sure why
https://codereview.chromium.org/2357723002

[tbansal1, 2017/02/23 23:54:05]

It was necessary for older testing framework. It should not be required now.

[megjablon, 2017/02/23 23:58:17]

Good to know. Done.

+
+      test_driver.LoadURL('http://check.googlezip.net/test.html')
+
+      lite_page_responses = 0
+      for response in test_driver.GetHTTPResponses():
+        if '/csi?' in response.url:
+          continue
+        if response.url.startswith('data:'):
+          continue
+        self.assertHasChromeProxyViaHeader(response)
+        chrome_proxy_request = response.request_headers['chrome-proxy']
+        cpat_request = response.request_headers['chrome-proxy-accept-transform']
+        cpct_response = response.response_headers[
+                          'chrome-proxy-content-transform']
+        if ('lite-page' in cpct_response):
+          lite_page_responses = lite_page_responses + 1
+          self.assertTrue('lite-page' in cpat_request)

[tbansal1, 2017/02/23 23:35:21]

Should not these 2 assertions be always true (regardless of whether lite-page
was present in cpct-response)?

If yes, then you can move these out of the if-conditional.

[megjablon, 2017/02/23 23:47:52]

For the first one, no, we should only request on the main frame so there should
only really be one request and response with lite-page directives. Changed the
very last assertion in the test based on this.

Second one I moved outside. 

[tbansal1, 2017/02/23 23:54:05]

Acknowledged.

+          self.assertTrue('exp=ignore_preview_blacklist' in
+            chrome_proxy_request)
+
+      # Verify that Lite Page responses were seen.
+      self.assertNotEqual(0, lite_page_responses)
+
 if __name__ == '__main__':
   IntegrationTest.RunAllTests()