Add workerReady timing for ServiceWorker controlled requests [1/3]

public/platform/WebURLLoadTiming.h

Index: public/platform/WebURLLoadTiming.h
diff --git a/public/platform/WebURLLoadTiming.h b/public/platform/WebURLLoadTiming.h
index da92eb1e872e134353c59529e8bce30fa4c6b224..8193c21b1e35c52084b822d72e93d81a9ef8149f 100644
--- a/public/platform/WebURLLoadTiming.h
+++ b/public/platform/WebURLLoadTiming.h
@@ -80,6 +80,9 @@ public:
     BLINK_PLATFORM_EXPORT double workerStart() const;
     BLINK_PLATFORM_EXPORT void setWorkerStart(double);
 
+    BLINK_PLATFORM_EXPORT double workerReady() const;
+    BLINK_PLATFORM_EXPORT void setWorkerReady(double);
+
     BLINK_PLATFORM_EXPORT double sendStart() const;
     BLINK_PLATFORM_EXPORT void setSendStart(double);