Stop Service Workers that execute JavaScript for too long.

content/renderer/service_worker/service_worker_script_context.cc

Index: content/renderer/service_worker/service_worker_script_context.cc
diff --git a/content/renderer/service_worker/service_worker_script_context.cc b/content/renderer/service_worker/service_worker_script_context.cc
index 372c7b9fbcd67cc9e6adbad3d007cb1b0d0f2c9a..61c83be92c07d65acefa1f12d5b4f623131b33db 100644
--- a/content/renderer/service_worker/service_worker_script_context.cc
+++ b/content/renderer/service_worker/service_worker_script_context.cc
@@ -127,6 +127,7 @@ void ServiceWorkerScriptContext::OnMessageReceived(
     IPC_MESSAGE_HANDLER(ServiceWorkerMsg_DidSkipWaiting, OnDidSkipWaiting)
     IPC_MESSAGE_HANDLER(ServiceWorkerMsg_DidClaimClients, OnDidClaimClients)
     IPC_MESSAGE_HANDLER(ServiceWorkerMsg_ClaimClientsError, OnClaimClientsError)
+    IPC_MESSAGE_HANDLER(ServiceWorkerMsg_Ping, OnPing);
     IPC_MESSAGE_UNHANDLED(handled = false)
   IPC_END_MESSAGE_MAP()
 
@@ -582,4 +583,8 @@ void ServiceWorkerScriptContext::OnClaimClientsError(
   pending_claim_clients_callbacks_.Remove(request_id);
 }
 
+void ServiceWorkerScriptContext::OnPing() {
+  Send(new ServiceWorkerHostMsg_Pong(GetRoutingID()));
+}
+
 }  // namespace content