Implement request's redirect mode and RequestRedirect for Fetch

public/platform/WebURLRequest.h

Index: public/platform/WebURLRequest.h
diff --git a/public/platform/WebURLRequest.h b/public/platform/WebURLRequest.h
index aa692f9da6f2a9cd35c9623247186ea501c44527..4ae27f3e9a5db2d05f9d56e6590f9f5eef27690c 100644
--- a/public/platform/WebURLRequest.h
+++ b/public/platform/WebURLRequest.h
@@ -122,6 +122,12 @@ public:
         FetchCredentialsModeInclude
     };
 
+    enum FetchRedirectMode {
+        FetchRedirectModeFollow,
+        FetchRedirectModeError,
+        FetchRedirectModeManual
+    };
+
     // Used to report performance metrics timed from the UI action that
     // triggered them (as opposed to navigation start time used in the
     // Navigation Timing API).
@@ -252,6 +258,10 @@ public:
     BLINK_PLATFORM_EXPORT FetchCredentialsMode fetchCredentialsMode() const;
     BLINK_PLATFORM_EXPORT void setFetchCredentialsMode(FetchCredentialsMode);
 
+    // The redirect mode which will be passed to the ServiceWorker.
+    BLINK_PLATFORM_EXPORT FetchRedirectMode fetchRedirectMode() const;
+    BLINK_PLATFORM_EXPORT void setFetchRedirectMode(FetchRedirectMode);
+
     // Extra data associated with the underlying resource request. Resource
     // requests can be copied. If non-null, each copy of a resource requests
     // holds a pointer to the extra data, and the extra data pointer will be