Revert of Revert of Revert of Flip extension background page throttling on by default

extensions/browser/extension_host.cc

 // Copyright 2014 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 "extensions/browser/extension_host.h"
 
 #include "base/logging.h"
 #include "base/metrics/field_trial.h"
 #include "base/metrics/histogram_macros.h"
 #include "base/profiler/scoped_tracker.h"
@@ skipping 135 matching lines @@
       FROM_HERE_WITH_EXPLICIT_FUNCTION(
           "464206 ExtensionHost::CreateRenderViewNow1"));
   LoadInitialURL();
   if (IsBackgroundPage()) {
     // TODO(robliao): Remove ScopedTracker below once crbug.com/464206 is fixed.
     tracked_objects::ScopedTracker tracking_profile2(
         FROM_HERE_WITH_EXPLICIT_FUNCTION(
             "464206 ExtensionHost::CreateRenderViewNow2"));
     DCHECK(IsRenderViewLive());
     if (extension_) {
-      if (extensions::BackgroundInfo::HasPersistentBackgroundPage(extension_) &&
-          base::FieldTrialList::FindFullName(
-              "ThrottleExtensionBackgroundPages") != "Disabled") {
+      std::string group_name = base::FieldTrialList::FindFullName(
+          "ThrottleExtensionBackgroundPages");
+      if ((group_name == "ThrottlePersistent" &&
+           extensions::BackgroundInfo::HasPersistentBackgroundPage(
+               extension_)) ||
+          group_name == "ThrottleAll") {
         host_contents_->WasHidden();
       }
     }
     // TODO(robliao): Remove ScopedTracker below once crbug.com/464206 is fixed.
     tracked_objects::ScopedTracker tracking_profile3(
         FROM_HERE_WITH_EXPLICIT_FUNCTION(
             "464206 ExtensionHost::CreateRenderViewNow3"));
     // Connect orphaned dev-tools instances.
     delegate_->OnRenderViewCreatedForBackgroundPage(this);
   }
@@ skipping 299 matching lines @@
       UMA_HISTOGRAM_MEDIUM_TIMES("Extensions.BackgroundPageLoadTime2",
                                  load_start_->Elapsed());
     }
   } else if (extension_host_type_ == VIEW_TYPE_EXTENSION_POPUP) {
     UMA_HISTOGRAM_MEDIUM_TIMES("Extensions.PopupLoadTime2",
                                load_start_->Elapsed());
   }
 }
 
 }  // namespace extensions