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

Index: chrome/browser/chrome_browser_field_trials.cc
diff --git a/chrome/browser/chrome_browser_field_trials.cc b/chrome/browser/chrome_browser_field_trials.cc
index ba85b4caf772cb6e337e662945c30ae3c15bb520..9cb0804b005927b7cb645dcc51dd1d32cbb2334d 100644
--- a/chrome/browser/chrome_browser_field_trials.cc
+++ b/chrome/browser/chrome_browser_field_trials.cc
@@ -69,6 +69,14 @@ void ChromeBrowserFieldTrials::SetupFieldTrials(PrefService* local_state) {
 #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(
@@ -125,6 +133,38 @@ void ChromeBrowserFieldTrials::SpdyFieldTrial() {
   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() {