Remove DeferBackgroundExtensionCreation field trial and supporting code

chrome/browser/profiles/profile_manager.cc

Index: chrome/browser/profiles/profile_manager.cc
diff --git a/chrome/browser/profiles/profile_manager.cc b/chrome/browser/profiles/profile_manager.cc
index 5724d71e74da86b011d964a774149c8535a8ccb2..d8963f1e5e65f153434cf16c4c30fca948fc9fa8 100644
--- a/chrome/browser/profiles/profile_manager.cc
+++ b/chrome/browser/profiles/profile_manager.cc
@@ -13,7 +13,6 @@
 #include "base/file_util.h"
 #include "base/files/file_enumerator.h"
 #include "base/files/file_path.h"
-#include "base/metrics/field_trial.h"
 #include "base/metrics/histogram.h"
 #include "base/prefs/pref_service.h"
 #include "base/prefs/scoped_user_pref_update.h"
@@ -788,37 +787,8 @@ void ProfileManager::DoFinalInit(Profile* profile, bool go_off_the_record) {
 void ProfileManager::DoFinalInitForServices(Profile* profile,
                                             bool go_off_the_record) {
 #if defined(ENABLE_EXTENSIONS)
-  // Set up a field trial to determine the effectiveness of deferring
-  // creation of background extension RenderViews.
-  CR_DEFINE_STATIC_LOCAL(scoped_refptr<base::FieldTrial>, trial, ());
-  static bool defer_creation = false;
-
-  if (!trial.get()) {
-    const base::FieldTrial::Probability kDivisor = 100;
-
-    // Enable the deferred creation for 50% of the users.
-    base::FieldTrial::Probability probability_per_group = 50;
-
-    // After August 31, 2014 builds, it will always be in default group
-    // (defer_creation == false).
-    trial = base::FieldTrialList::FactoryGetFieldTrial(
-        "DeferBackgroundExtensionCreation",
-        kDivisor,
-        "RateLimited",
-        2014,
-        8,
-        31,
-        base::FieldTrial::ONE_TIME_RANDOMIZED,
-        NULL);
-
-    // Add group for deferred creation of background extension RenderViews.
-    int defer_creation_group =
-        trial->AppendGroup("Deferred", probability_per_group);
-    defer_creation = trial->group() == defer_creation_group;
-  }
-
   extensions::ExtensionSystem::Get(profile)->InitForRegularProfile(
-      !go_off_the_record, defer_creation);
+      !go_off_the_record);
   // During tests, when |profile| is an instance of TestingProfile,
   // ExtensionSystem might not create an ExtensionService.
   if (extensions::ExtensionSystem::Get(profile)->extension_service()) {