Turn on ServiceWorkerOnUI by default

Bug: 824858
Change-Id: I28cae38ddfa0dd451917ce699868e722f5ffb177
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2407628
Commit-Queue: Makoto Shimazu <shimazu@chromium.org>
Commit-Queue: Matt Falkenhagen <falken@chromium.org>
Auto-Submit: Makoto Shimazu <shimazu@chromium.org>
Reviewed-by: Matt Falkenhagen <falken@chromium.org>
Cr-Commit-Position: refs/heads/master@{#806557}

content/public/common/content_features.cc

@@ -575,7 +575,7 @@ const base::Feature kSendBeaconThrowForBlobWithNonSimpleType{
 // IO thread.
 // https://crbug.com/824858
 const base::Feature kServiceWorkerOnUI{"ServiceWorkerOnUI",
-                                       base::FEATURE_DISABLED_BY_DEFAULT};
+                                       base::FEATURE_ENABLED_BY_DEFAULT};
 
 // Service worker based payment apps as defined by w3c here:
 // https://w3c.github.io/webpayments-payment-apps-api/