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

extensions/browser/extension_host.cc

Index: extensions/browser/extension_host.cc
diff --git a/extensions/browser/extension_host.cc b/extensions/browser/extension_host.cc
index edeb7461878b652ba798e6e166b0ba565816cf5a..0afeb4338c865c058fe79e77f80c98d5dc39e069 100644
--- a/extensions/browser/extension_host.cc
+++ b/extensions/browser/extension_host.cc
@@ -153,9 +153,12 @@
             "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();
       }
     }