Implement the LoFi 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
new file mode 100644
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--- /dev/null
+++ b/tools/chrome_proxy/webdriver/lofi.py
@@ -0,0 +1,46 @@
+# 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
+
+
+class LoFi(IntegrationTest):
+
+  #  Checks that the compressed image is below a certain threshold.
+  #  The test page is uncacheable otherwise a cached page may be served that
+  #  doesn't have the correct via headers.
+  def testLoFi(self):
+    with TestDriver() as test_driver:
+      test_driver.AddChromeArg('--enable-spdy-proxy-auth')
+      test_driver.AddChromeArg('--data-reduction-proxy-lo-fi=always-on')
+      # Disable server experiments such as tamper detection.
+      test_driver.AddChromeArg('--data-reduction-proxy-server-experiments-'
+                               'disabled')
+      test_driver.AddChromeArg('--disable-quic')
+
+      test_driver.LoadURL('http://check.googlezip.net/static/index.html')
+
+      lofi_responses = 0
+      for response in test_driver.GetHTTPResponses():
+        if not response.url.endswith('png'):
+          continue
+        if not response.request_headers:
+          continue
+        self.assertHasChromeProxyViaHeader(response)
+        content_length = response.response_headers['content-length']
+        cpat_request = response.request_headers['chrome-proxy-accept-transform']
+        cpct_response = response.response_headers[
+                          'chrome-proxy-content-transform']
+        if ('empty-image' in cpct_response):
+          lofi_responses = lofi_responses + 1
+          self.assertIn('empty-image', cpat_request)
+          self.assertTrue(int(content_length) < 100)
+
+      # Verify that Lo-Fi responses were seen.
+      self.assertNotEqual(0, lofi_responses)
+
+if __name__ == '__main__':
+  IntegrationTest.RunAllTests()