Reduce fieldtrials percentages for push to stable M7

In one case, completely removed the field trial.

BUG=55634
r=mbelshe,willchan
Review URL: http://codereview.chromium.org/3449003

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@59614 0039d316-1c4b-4281-b951-d872f2087c98

3 files changed, 18 insertions, 54 deletions

diff --git a/chrome/browser/browser_main.cc b/chrome/browser/browser_main.cc
index be78ce6..cd3cc4f 100644
--- a/chrome/browser/browser_main.cc
+++ b/chrome/browser/browser_main.cc
@@ -246,8 +246,8 @@ void BrowserMainParts::ConnectionFieldTrial() {
 // packet and possibly another RTT to re-establish the connection.
 void BrowserMainParts::SocketTimeoutFieldTrial() {
   const FieldTrial::Probability kIdleSocketTimeoutDivisor = 100;
-  // 25% probability
-  const FieldTrial::Probability kSocketTimeoutProbability = 25;
+  // 1% probability for all experimental settings.
+  const FieldTrial::Probability kSocketTimeoutProbability = 1;
 
   scoped_refptr<FieldTrial> socket_timeout_trial =
       new FieldTrial("IdleSktToImpact", kIdleSocketTimeoutDivisor);
@@ -255,19 +255,14 @@ void BrowserMainParts::SocketTimeoutFieldTrial() {
   const int socket_timeout_5 =
       socket_timeout_trial->AppendGroup("idle_timeout_5",
                                         kSocketTimeoutProbability);
+  const int socket_timeout_10 =
+      socket_timeout_trial->AppendGroup("idle_timeout_10",
+                                        kSocketTimeoutProbability);
   const int socket_timeout_20 =
       socket_timeout_trial->AppendGroup("idle_timeout_20",
                                         kSocketTimeoutProbability);
   const int socket_timeout_60 =
       socket_timeout_trial->AppendGroup("idle_timeout_60",
-                                        kSocketTimeoutProbability);
-  // This (10 seconds) is the current default value. Declaring it at the end
-  // allows for assigning the remainder of the probability space to it; which
-  // will make it to modify this value (by changing |kSocketTimeoutProbability|)
-  // down the road if we see the need to, while the remaining groups are
-  // are assigned an equal share of the probability space.
-  const int socket_timeout_10 =
-      socket_timeout_trial->AppendGroup("idle_timeout_10",
                                         FieldTrial::kAllRemainingProbability);
 
   const int idle_to_trial_group = socket_timeout_trial->group();
@@ -339,18 +334,14 @@ void BrowserMainParts::SpdyFieldTrial() {
     net::HttpNetworkLayer::EnableSpdy(spdy_mode);
   } else {
     const FieldTrial::Probability kSpdyDivisor = 1000;
-    // To enable 100% npn_with_spdy, set npnhttp_probability = 0 and set
-    // npnspdy_probability = FieldTrial::kAllRemainingProbability.
-    FieldTrial::Probability npnhttp_probability = 50;
-    FieldTrial::Probability npnspdy_probability = 950;
+    FieldTrial::Probability npnhttp_probability = 10;  // 1% to preclude SPDY.
     scoped_refptr<FieldTrial> trial =
         new FieldTrial("SpdyImpact", kSpdyDivisor);
     // npn with only http support, no spdy.
-    int npn_http_grp =
-        trial->AppendGroup("npn_with_http", npnhttp_probability);
+    int npn_http_grp = trial->AppendGroup("npn_with_http", npnhttp_probability);
     // npn with spdy support.
-    int npn_spdy_grp =
-        trial->AppendGroup("npn_with_spdy", npnspdy_probability);
+    int npn_spdy_grp = trial->AppendGroup("npn_with_spdy",
+                                          FieldTrial::kAllRemainingProbability);
     int trial_grp = trial->group();
     if (trial_grp == npn_http_grp) {
       is_spdy_trial = true;
@@ -365,7 +356,7 @@ void BrowserMainParts::SpdyFieldTrial() {
 }
 
 // If neither --enable-content-prefetch or --disable-content-prefetch
-// is set, users will be in an A/B test for prefetching.
+// is set, users will not be in an A/B test for prefetching.
 void BrowserMainParts::PrefetchFieldTrial() {
   if (parsed_command_line().HasSwitch(switches::kEnableContentPrefetch))
     ResourceDispatcherHost::set_is_prefetch_enabled(true);
@@ -400,14 +391,14 @@ void BrowserMainParts::ConnectBackupJobsFieldTrial() {
   } else {
     const FieldTrial::Probability kConnectBackupJobsDivisor = 100;
     // 50% probability.
-    const FieldTrial::Probability kConnectBackupJobsProbability = 50;
-    scoped_refptr<FieldTrial> trial =
-      new FieldTrial("ConnnectBackupJobs", kConnectBackupJobsDivisor);
+    const FieldTrial::Probability kConnectBackupJobsProbability = 1;  // 1%.
+    scoped_refptr<FieldTrial> trial = new FieldTrial("ConnnectBackupJobs",
+                                                     kConnectBackupJobsDivisor);
+    trial->AppendGroup("ConnectBackupJobsDisabled",
+                       kConnectBackupJobsProbability);
     const int connect_backup_jobs_enabled =
         trial->AppendGroup("ConnectBackupJobsEnabled",
-            kConnectBackupJobsProbability);
-    trial->AppendGroup("ConnectBackupJobsDisabled",
-                       FieldTrial::kAllRemainingProbability);
+                           FieldTrial::kAllRemainingProbability);
     const int trial_group = trial->group();
     net::internal::ClientSocketPoolBaseHelper::set_connect_backup_jobs_enabled(
         trial_group == connect_backup_jobs_enabled);
diff --git a/chrome/browser/io_thread.cc b/chrome/browser/io_thread.cc
index 3780118..f361b77 100644
--- a/chrome/browser/io_thread.cc
+++ b/chrome/browser/io_thread.cc
@@ -57,26 +57,8 @@ net::HostResolver* CreateGlobalHostResolver(net::NetLog* net_log) {
       net::HostResolverImpl* host_resolver_impl =
           global_host_resolver->GetAsHostResolverImpl();
       if (host_resolver_impl != NULL) {
-        // (optionally) Use probe to decide if support is warranted.
-        bool use_ipv6_probe = true;
-
-#if defined(OS_WIN)
-        // Measure impact of probing to allow IPv6.
-        // Some users report confused OS handling of IPv6, leading to large
-        // latency.  If we can show that IPv6 is not supported, then disabliing
-        // it will work around such problems. This is the test of the probe.
-        const FieldTrial::Probability kDivisor = 100;
-        const FieldTrial::Probability kProbability = 50;  // 50% probability.
-        FieldTrial* trial = new FieldTrial("IPv6_Probe", kDivisor);
-        int skip_group = trial->AppendGroup("IPv6_probe_skipped",
-                                            kProbability);
-        trial->AppendGroup("IPv6_probe_done",
-                           FieldTrial::kAllRemainingProbability);
-        use_ipv6_probe = (trial->group() != skip_group);
-#endif
-
-        if (use_ipv6_probe)
-          host_resolver_impl->ProbeIPv6Support();
+        // Use probe to decide if support is warranted.
+        host_resolver_impl->ProbeIPv6Support();
       }
     }
   }
diff --git a/chrome/browser/net/url_info.cc b/chrome/browser/net/url_info.cc
index cd065de..7daf500 100644
--- a/chrome/browser/net/url_info.cc
+++ b/chrome/browser/net/url_info.cc
@@ -122,15 +122,6 @@ void UrlInfo::SetFoundState() {
   if (kMaxNonNetworkDnsLookupDuration <= resolve_duration_) {
     UMA_HISTOGRAM_CUSTOM_TIMES("DNS.PrefetchResolution", resolve_duration_,
         kMaxNonNetworkDnsLookupDuration, TimeDelta::FromMinutes(15), 100);
-
-    static bool use_ipv6_histogram(FieldTrialList::Find("IPv6_Probe") &&
-        !FieldTrialList::Find("IPv6_Probe")->group_name().empty());
-    if (use_ipv6_histogram) {
-      UMA_HISTOGRAM_CUSTOM_TIMES(
-          FieldTrial::MakeName("DNS.PrefetchResolution", "IPv6_Probe"),
-          resolve_duration_, kMaxNonNetworkDnsLookupDuration,
-          TimeDelta::FromMinutes(15), 100);
-    }
   }
   sequence_number_ = sequence_counter++;
   DLogResultsStats("DNS PrefetchFound");