Send Finch experiment selection data to ad-service at Google so QUIC performance can be evaluated

chrome/browser/metrics/variations/variations_http_header_provider.cc

 // Copyright (c) 2012 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.
 
 #include "chrome/browser/metrics/variations/variations_http_header_provider.h"
 
 #include <vector>
 
 #include "base/base64.h"
 #include "base/memory/singleton.h"
@@ skipping 12 matching lines @@
 VariationsHttpHeaderProvider* VariationsHttpHeaderProvider::GetInstance() {
   return Singleton<VariationsHttpHeaderProvider>::get();
 }
 
 void VariationsHttpHeaderProvider::AppendHeaders(
     const GURL& url,
     bool incognito,
     bool uma_enabled,
     net::HttpRequestHeaders* headers) {
   // Note the criteria for attaching Chrome experiment headers:
-  // 1. We only transmit to *.google.<TLD> or *.youtube.<TLD> domains.
+  // 1. We only transmit to Google owned domains which can evaluate experiments.
+  //    1a. These include hosts which have a standard postfix such as:
+  //         *.doubleclick.net or *.googlesyndication.com or
+  //         exactly www.googleadservices.com or
+  //         international TLD domains *.google.<TLD> or *.youtube.<TLD>.
   // 2. Only transmit for non-Incognito profiles.
   // 3. For the X-Chrome-UMA-Enabled bit, only set it if UMA is in fact enabled
   //    for this install of Chrome.
   // 4. For the X-Client-Data header, only include non-empty variation IDs.
   if (incognito || !ShouldAppendHeaders(url))
     return;
 
   if (uma_enabled)
     headers->SetHeaderIfMissing("X-Chrome-UMA-Enabled", "1");
 
@@ skipping 127 matching lines @@
   variation_ids_header_ = hashed;
 }
 
 // static
 bool VariationsHttpHeaderProvider::ShouldAppendHeaders(const GURL& url) {
   if (google_util::IsGoogleDomainUrl(url, google_util::ALLOW_SUBDOMAIN,
                                      google_util::ALLOW_NON_STANDARD_PORTS)) {
     return true;
   }
 
-  // The below mirrors logic in IsGoogleDomainUrl(), but for youtube.<TLD>.
   if (!url.is_valid() || !url.SchemeIsHTTPOrHTTPS())
     return false;
 
+  // Some domains don't have international TLD extensions, so testing for them
+  // is very straight forward.
   const std::string host = url.host();
+  if (EndsWith(host, ".doubleclick.net", false) ||
+      EndsWith(host, ".googlesyndication.com", false) ||
+      LowerCaseEqualsASCII(host, "www.googleadservices.com"))

[Alexei Svitkine (slow), 2014/04/01 15:16:48]

Nit: {}'s

(Some reviewers disagree on this, but in Variations code, we use {}'s when
either the if or the body spans multiple lines.)

[jar (doing other things), 2014/04/01 16:55:42]

Done.  (and I agree with the nit change... my fault for missing it).

+    return true;
+
+  // The below mirrors logic in IsGoogleDomainUrl(), but for youtube.<TLD>.
   const size_t tld_length = net::registry_controlled_domains::GetRegistryLength(
       host,
       net::registry_controlled_domains::EXCLUDE_UNKNOWN_REGISTRIES,
       net::registry_controlled_domains::EXCLUDE_PRIVATE_REGISTRIES);
   if ((tld_length == 0) || (tld_length == std::string::npos))
     return false;
 
   const std::string host_minus_tld(host, 0, host.length() - tld_length);
   return LowerCaseEqualsASCII(host_minus_tld, "youtube.") ||
       EndsWith(host_minus_tld, ".youtube.", false);
 }
 
 }  // namespace chrome_variations