Revert "net: add DNS revocation experiment."

The reverts r127994 as the experiment has concluded.

BUG=none
TEST=none

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@131620 0039d316-1c4b-4281-b951-d872f2087c98

4 files changed, 0 insertions, 136 deletions

diff --git a/chrome/browser/chrome_browser_main.cc b/chrome/browser/chrome_browser_main.cc
index 14c5dee..3cca0dd 100644
--- a/chrome/browser/chrome_browser_main.cc
+++ b/chrome/browser/chrome_browser_main.cc
@@ -57,7 +57,6 @@
 #include "chrome/browser/metrics/tracking_synchronizer.h"
 #include "chrome/browser/nacl_host/nacl_process_host.h"
 #include "chrome/browser/net/chrome_net_log.h"
-#include "chrome/browser/net/chrome_network_delegate.h"
 #include "chrome/browser/net/predictor.h"
 #include "chrome/browser/notifications/desktop_notification_service.h"
 #include "chrome/browser/notifications/desktop_notification_service_factory.h"
@@ -993,22 +992,6 @@ void ChromeBrowserMainParts::AutoLaunchChromeFieldTrial() {
   }
 }
 
-void ChromeBrowserMainParts::ComodoDNSExperimentFieldTrial() {
-  // 100% probability of being in the experiment group until the timeout.
-  const base::FieldTrial::Probability kDivisor = 1;
-  const base::FieldTrial::Probability kProbability = 1;
-
-  // After April 15, 2012 builds, it will always be in default group.
-  scoped_refptr<base::FieldTrial> trial(
-      new base::FieldTrial("ComodoDNSExperiment", kDivisor,
-          "inactive", 2012, 4, 15));
-
-  const int active = trial->AppendGroup("active", kProbability);
-
-  if (trial->group() == active)
-    ChromeNetworkDelegate::EnableComodoDNSExperiment();
-}
-
 // ChromeBrowserMainParts: |SetupMetricsAndFieldTrials()| related --------------
 
 void ChromeBrowserMainParts::SetupFieldTrials(bool metrics_recording_enabled,
@@ -1029,7 +1012,6 @@ void ChromeBrowserMainParts::SetupFieldTrials(bool metrics_recording_enabled,
   PredictorFieldTrial();
   DefaultAppsFieldTrial();
   AutoLaunchChromeFieldTrial();
-  ComodoDNSExperimentFieldTrial();
   AutocompleteFieldTrial::Activate();
   NewTabUI::SetupFieldTrials();
 }
diff --git a/chrome/browser/chrome_browser_main.h b/chrome/browser/chrome_browser_main.h
index 4cafccd..2f75057 100644
--- a/chrome/browser/chrome_browser_main.h
+++ b/chrome/browser/chrome_browser_main.h
@@ -127,10 +127,6 @@ class ChromeBrowserMainParts : public content::BrowserMainParts {
   // computer startup has on retention and usage of Chrome.
   void AutoLaunchChromeFieldTrial();
 
-  // A field trial to test the viability of a DNS based, certificate revocation
-  // system.
-  void ComodoDNSExperimentFieldTrial();
-
   // Methods for |SetupMetricsAndFieldTrials()| --------------------------------
 
   // Constructs metrics service and does related initialization, including
diff --git a/chrome/browser/net/chrome_network_delegate.cc b/chrome/browser/net/chrome_network_delegate.cc
index cb88f30..545d127 100644
--- a/chrome/browser/net/chrome_network_delegate.cc
+++ b/chrome/browser/net/chrome_network_delegate.cc
@@ -4,9 +4,7 @@
 
 #include "chrome/browser/net/chrome_network_delegate.h"
 
-#include "base/base64.h"
 #include "base/logging.h"
-#include "base/metrics/histogram.h"
 #include "chrome/browser/browser_process.h"
 #include "chrome/browser/content_settings/cookie_settings.h"
 #include "chrome/browser/content_settings/tab_specific_content_settings.h"
@@ -24,11 +22,8 @@
 #include "content/public/browser/render_view_host.h"
 #include "content/public/browser/resource_request_info.h"
 #include "net/base/host_port_pair.h"
-#include "net/base/dns_util.h"
-#include "net/base/dnsrr_resolver.h"
 #include "net/base/net_errors.h"
 #include "net/base/net_log.h"
-#include "net/base/public_key_hashes.h"
 #include "net/cookies/cookie_monster.h"
 #include "net/http/http_request_headers.h"
 #include "net/http/http_response_headers.h"
@@ -108,66 +103,6 @@ void ForwardRequestStatus(
   }
 }
 
-const char* const kComodoCerts[] = {
-  kSPKIHash_AAACertificateServices,
-  kSPKIHash_AddTrustClass1CARoot,
-  kSPKIHash_AddTrustExternalCARoot,
-  kSPKIHash_AddTrustPublicCARoot,
-  kSPKIHash_AddTrustQualifiedCARoot,
-  kSPKIHash_COMODOCertificationAuthority,
-  kSPKIHash_SecureCertificateServices,
-  kSPKIHash_TrustedCertificateServices,
-  kSPKIHash_UTNDATACorpSGC,
-  kSPKIHash_UTNUSERFirstClientAuthenticationandEmail,
-  kSPKIHash_UTNUSERFirstHardware,
-  kSPKIHash_UTNUSERFirstObject,
-};
-
-// IsComodoCertificate returns true if a known Comodo public key appears in
-// |public_key_hashes|.
-// TODO(agl): remove once experiment is complete, by July 2012.
-static bool IsComodoCertificate(
-    const std::vector<net::SHA1Fingerprint>& public_key_hashes) {
-  for (std::vector<net::SHA1Fingerprint>::const_iterator
-       i = public_key_hashes.begin(); i != public_key_hashes.end(); ++i) {
-    std::string base64_hash;
-    base::Base64Encode(
-        base::StringPiece(reinterpret_cast<const char*>(i->data),
-                          arraysize(i->data)),
-        &base64_hash);
-    base64_hash = "sha1/" + base64_hash;
-
-    for (size_t j = 0; j < arraysize(kComodoCerts); j++) {
-      if (base64_hash == kComodoCerts[j])
-        return true;
-    }
-  }
-
-  return false;
-}
-
-// RecordComodoDNSResult is a callback from a DNS resolution. It records the
-// elapsed time in a histogram.
-// TODO(agl): remove once experiment is complete, by July 2012.
-static void RecordComodoDNSResult(net::RRResponse* response,
-                                  base::TimeTicks start_time,
-                                  int result) {
-  base::TimeDelta total_time = base::TimeTicks::Now() - start_time;
-  if (total_time.InMilliseconds() > 10) {
-    // If the reply took > 10 ms there's a good chance that it didn't come from
-    // a local DNS cache.
-    if (result == net::OK &&
-        response->rrdatas.size() &&
-        response->rrdatas[0].find("wibble") != std::string::npos) {
-      UMA_HISTOGRAM_TIMES("Net.ComodoDNSExperimentSuccessTime", total_time);
-    } else {
-      UMA_HISTOGRAM_TIMES("Net.ComodoDNSExperimentFailureTime", total_time);
-    }
-  }
-}
-
-bool g_comodo_dns_experiment_enabled = false;
-
 }  // namespace
 
 ChromeNetworkDelegate::ChromeNetworkDelegate(
@@ -199,11 +134,6 @@ void ChromeNetworkDelegate::InitializeReferrersEnabled(
   enable_referrers->MoveToThread(BrowserThread::IO);
 }
 
-// static
-void ChromeNetworkDelegate::EnableComodoDNSExperiment() {
-  g_comodo_dns_experiment_enabled = true;
-}
-
 int ChromeNetworkDelegate::OnBeforeURLRequest(
     net::URLRequest* request,
     const net::CompletionCallback& callback,
@@ -267,40 +197,6 @@ void ChromeNetworkDelegate::OnResponseStarted(net::URLRequest* request) {
   ExtensionWebRequestEventRouter::GetInstance()->OnResponseStarted(
       profile_, extension_info_map_.get(), request);
   ForwardProxyErrors(request, event_router_.get(), profile_);
-
-  if (g_comodo_dns_experiment_enabled) {
-    // This is a temporary experiment, in conjuction with Comodo, to measure the
-    // effectiveness of a possible DNS-based revocation mechanism.
-    // TODO(agl): remove once experiment is complete, by July 2012.
-    const net::SSLInfo& ssl_info = request->response_info().ssl_info;
-    if (request->response_info().was_cached == false &&
-        ssl_info.is_valid() &&
-        ssl_info.is_issued_by_known_root &&
-        IsComodoCertificate(ssl_info.public_key_hashes)) {
-      if (dnsrr_resolver_.get() == NULL)
-        dnsrr_resolver_.reset(new net::DnsRRResolver);
-
-      // The Comodo DNS record has a 20 minute TTL, so we won't actually
-      // request it more than three times an hour because it'll be in the
-      // DnsRRResolver's cache. However, just in case something goes wrong we
-      // also implement a hard stop to prevent resolutions more than once
-      // every ten minutes.
-      const base::TimeTicks now(base::TimeTicks::Now());
-      if (!last_comodo_resolution_time_.is_null() &&
-          (now - last_comodo_resolution_time_).InMinutes() < 10) {
-        return;
-      }
-      last_comodo_resolution_time_ = now;
-
-      net::RRResponse* response = new net::RRResponse;
-      base::TimeTicks start_time(now);
-      dnsrr_resolver_->Resolve(
-          "wibble.comodoca.com", net::kDNS_TXT, 0 /* flags */,
-          Bind(RecordComodoDNSResult, base::Owned(response), start_time),
-          response, 0 /* priority */,
-          request->net_log());
-    }
-  }
 }
 
 void ChromeNetworkDelegate::OnRawBytesRead(const net::URLRequest& request,
diff --git a/chrome/browser/net/chrome_network_delegate.h b/chrome/browser/net/chrome_network_delegate.h
index 7abf351..a582c38 100644
--- a/chrome/browser/net/chrome_network_delegate.h
+++ b/chrome/browser/net/chrome_network_delegate.h
@@ -9,7 +9,6 @@
 #include "base/basictypes.h"
 #include "base/compiler_specific.h"
 #include "base/memory/ref_counted.h"
-#include "base/time.h"
 #include "net/base/network_delegate.h"
 
 class CookieSettings;
@@ -24,10 +23,6 @@ namespace policy {
 class URLBlacklistManager;
 }
 
-namespace net {
-class DnsRRResolver;
-}
-
 // ChromeNetworkDelegate is the central point from within the chrome code to
 // add hooks into the network stack.
 class ChromeNetworkDelegate : public net::NetworkDelegate {
@@ -52,8 +47,6 @@ class ChromeNetworkDelegate : public net::NetworkDelegate {
   static void InitializeReferrersEnabled(BooleanPrefMember* enable_referrers,
                                          PrefService* pref_service);
 
-  static void EnableComodoDNSExperiment();
-
  private:
   // NetworkDelegate implementation.
   virtual int OnBeforeURLRequest(net::URLRequest* request,
@@ -102,9 +95,6 @@ class ChromeNetworkDelegate : public net::NetworkDelegate {
   // Weak, owned by our owner.
   const policy::URLBlacklistManager* url_blacklist_manager_;
 
-  scoped_ptr<net::DnsRRResolver> dnsrr_resolver_;
-  base::TimeTicks last_comodo_resolution_time_;
-
   DISALLOW_COPY_AND_ASSIGN(ChromeNetworkDelegate);
 };