[ServiceWorker] Add wasFetchedViaServiceWorker flag to WebURLResponse and ResourceResponse.

public/platform/WebURLResponse.h

Index: public/platform/WebURLResponse.h
diff --git a/public/platform/WebURLResponse.h b/public/platform/WebURLResponse.h
index 7649871285eaa0a3c4b597a77153ae24515cf841..37ee12cf9f197bc96e1340cc8713eaa827af5ade 100644
--- a/public/platform/WebURLResponse.h
+++ b/public/platform/WebURLResponse.h
@@ -166,6 +166,10 @@ public:
     BLINK_PLATFORM_EXPORT bool wasFetchedViaProxy() const;
     BLINK_PLATFORM_EXPORT void setWasFetchedViaProxy(bool);
 
+    // Flag whether this request was loaded via a ServiceWorker.
+    BLINK_PLATFORM_EXPORT bool wasFetchedViaServiceWorker() const;
+    BLINK_PLATFORM_EXPORT void setWasFetchedViaServiceWorker(bool);
+
     // Flag whether this request is part of a multipart response.
     BLINK_PLATFORM_EXPORT bool isMultipartPayload() const;
     BLINK_PLATFORM_EXPORT void setIsMultipartPayload(bool);