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 0afeb4338c865c058fe79e77f80c98d5dc39e069..309c4fa07b6920e6ad81b23ac01ef7b88f014d92 100644
--- a/extensions/browser/extension_host.cc
+++ b/extensions/browser/extension_host.cc
@@ -153,12 +153,9 @@ void ExtensionHost::CreateRenderViewNow() {
             "464206 ExtensionHost::CreateRenderViewNow2"));
     DCHECK(IsRenderViewLive());
     if (extension_) {
-      std::string group_name = base::FieldTrialList::FindFullName(
-          "ThrottleExtensionBackgroundPages");
-      if ((group_name == "ThrottlePersistent" &&
-           extensions::BackgroundInfo::HasPersistentBackgroundPage(
-               extension_)) ||
-          group_name == "ThrottleAll") {
+      if (base::FieldTrialList::FindFullName(

[not at google - send to devlin, 2015/04/23 18:35:04]

btw is looking up a field trial at all expensive? because the
HasPersistentBackgroundPage isn't at all... and I actually think it reads more
naturally if you check that first anyway.

[oystein (OOO til 10th of July), 2015/04/23 18:37:28]

Agreed; done.

+              "ThrottleExtensionBackgroundPages") != "disabled" &&

[not at google - send to devlin, 2015/04/23 18:35:04]

kinda weird that the case here changed, from "ThrottlePersistent"/"ThrottleAll"
to "disabled", but just an observation.

[oystein (OOO til 10th of July), 2015/04/23 18:37:27]

Fair enough :). Changed to "Disabled"

+          extensions::BackgroundInfo::HasPersistentBackgroundPage(extension_)) {
         host_contents_->WasHidden();
       }
     }