Tools/WebKitTestRunner/Configurations/WebKitTestRunnerApp-iOS.entitlements - WebKit - Git at Google

 <?xml version="1.0" encoding="UTF-8"?>
 <!DOCTYPE plist PUBLIC "-//Apple//DTD PLIST 1.0//EN" "http://www.apple.com/DTDs/PropertyList-1.0.dtd">
 <plist version="1.0">
 <dict>
 	<key>com.apple.developer.WebKit.ServiceWorkers</key>
     <true/>
 </dict>
 </plist>
	<?xml version="1.0" encoding="UTF-8"?>
	<!DOCTYPE plist PUBLIC "-//Apple//DTD PLIST 1.0//EN" "http://www.apple.com/DTDs/PropertyList-1.0.dtd">
	<plist version="1.0">
	<dict>
	<key>com.apple.developer.WebKit.ServiceWorkers</key>
	<true/>
	</dict>
	</plist>