Add method to invoke mobile only field trials. Add a field trial that controls rollout of data comp…

chrome/browser/chrome_browser_field_trials.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/chrome_browser_field_trials.h"
 
 #include <string>
 
 #include "apps/field_trial_names.h"
 #include "apps/pref_names.h"
@@ skipping 51 matching lines @@
 
 void ChromeBrowserFieldTrials::SetupFieldTrials(PrefService* local_state) {
   const base::Time install_time = base::Time::FromTimeT(
       local_state->GetInt64(prefs::kInstallDate));
   DCHECK(!install_time.is_null());
   chrome_variations::SetupUniformityFieldTrials(install_time);
   SetUpSimpleCacheFieldTrial();
 #if !defined(OS_ANDROID)
   SetupDesktopFieldTrials(local_state);
 #endif  // defined(OS_ANDROID)
+
+#if defined(OS_ANDROID) || defined(OS_IOS)
+  SetupMobileFieldTrials();
+#endif  // defined(OS_ANDROID) || defined(OS_IOS)
+}
+
+void ChromeBrowserFieldTrials::SetupMobileFieldTrials() {
+  DataCompressionProxyFieldTrial();
 }
 
 void ChromeBrowserFieldTrials::SetupDesktopFieldTrials(
     PrefService* local_state) {
   prerender::ConfigurePrefetchAndPrerender(parsed_command_line_);
   SpdyFieldTrial();
   WarmConnectionFieldTrial();
   AutoLaunchChromeFieldTrial();
   gpu_util::InitializeCompositingFieldTrial();
   OmniboxFieldTrial::ActivateStaticTrials();
@@ skipping 36 matching lines @@
   scoped_refptr<base::FieldTrial> trial(
       base::FieldTrialList::FactoryGetFieldTrial(
           "SpdyCwnd", kSpdyCwndDivisor, "cwndDynamic", 2013, 6, 30, NULL));
 
   trial->AppendGroup("cwnd10", kSpdyCwnd10);
   trial->AppendGroup("cwnd16", kSpdyCwnd16);
   trial->AppendGroup("cwndMin16", kSpdyCwndMin16);
   trial->AppendGroup("cwndMin10", kSpdyCwndMin10);
 }
 
+// Governs the rollout of the compression proxy for Chrome on mobile platforms.
+// Always enabled in DEV and BETA versions.
+// Stable percentage will be controlled from server.
+void ChromeBrowserFieldTrials::DataCompressionProxyFieldTrial() {
+  const char kDataCompressionProxyFieldTrialName[] =
+      "DataCompressionProxyRollout";
+  const base::FieldTrial::Probability kDataCompressionProxyDivisor = 1000;
+  const base::FieldTrial::Probability kDataCompressionProxyStable = 0;

[SteveT, 2013/03/29 17:40:55]

So what's the plan? Stable is zero for now, and we can merge a simple patch to
change this if things look good?

+  const char kEnabled[] = "Enabled";
+  const char kDisabled[] = "Disabled";
+
+  // Find out if this is a stable channel.
+  const bool kIsStableChannel =
+      chrome::VersionInfo::GetChannel() == chrome::VersionInfo::CHANNEL_STABLE;
+
+  // Experiment enabled until Jan 1, 2015. By default, disabled.
+  scoped_refptr<base::FieldTrial> trial(
+      base::FieldTrialList::FactoryGetFieldTrial(
+          kDataCompressionProxyFieldTrialName, kDataCompressionProxyDivisor,
+          kDisabled, 2015, 1, 1, NULL));
+
+  // Non-stable channels will run with probability 1.
+  const int kEnabledGroup = trial->AppendGroup(
+      kEnabled,
+      kIsStableChannel ?
+          kDataCompressionProxyStable : kDataCompressionProxyDivisor);
+
+  const int v = trial->group();
+  VLOG(1) << "DataCompression proxy enabled group id: " << kEnabledGroup
+          << ". Selected group id: " << v;
+}
+
 // If --socket-reuse-policy is not specified, run an A/B test for choosing the
 // warmest socket.
 void ChromeBrowserFieldTrials::WarmConnectionFieldTrial() {
   const CommandLine& command_line = parsed_command_line_;
   if (command_line.HasSwitch(switches::kSocketReusePolicy)) {
     std::string socket_reuse_policy_str = command_line.GetSwitchValueASCII(
         switches::kSocketReusePolicy);
     int policy = -1;
     base::StringToInt(socket_reuse_policy_str, &policy);
 
@@ skipping 148 matching lines @@
   // Call |FindValue()| on the trials below, which may come from the server, to
   // ensure they get marked as "used" for the purposes of data reporting.
   base::FieldTrialList::FindValue("UMA-Dynamic-Binary-Uniformity-Trial");
   base::FieldTrialList::FindValue("UMA-Dynamic-Uniformity-Trial");
   base::FieldTrialList::FindValue("InstantDummy");
   base::FieldTrialList::FindValue("InstantChannel");
   base::FieldTrialList::FindValue("Test0PercentDefault");
   // Activate the autocomplete dynamic field trials.
   OmniboxFieldTrial::ActivateDynamicTrials();
 }