Revert of Flip extension background page throttling on by default (pa…

…tchset #2 id:20001 of https://codereview.chromium.org/1106653002/)

Reason for revert:
Speculative revert - multiple browser_tests fail on Mac10.9 Tests (dbg)
http://goo.gl/4AqhVG

Original issue's description:
> Flip extension background page throttling on by default
>
> R=kalman
> BUG=424661
>
> Committed: https://crrev.com/34ea66b8ac1d56dadd670a9f5f8431063857ffdd
> Cr-Commit-Position: refs/heads/master@{#326953}

TBR=kalman@chromium.org,oysteine@chromium.org
NOPRESUBMIT=true
NOTREECHECKS=true
NOTRY=true
BUG=424661

Review URL: https://codereview.chromium.org/1106953002

Cr-Commit-Position: refs/heads/master@{#327021}

extensions/browser/extension_host.cc

@@ -153,9 +153,12 @@ void ExtensionHost::CreateRenderViewNow() {
             "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();
       }
     }