[1/3 blink] Support redirect option of Request and "opaqueredirect" response type.

public/platform/WebURLRequest.h

Index: public/platform/WebURLRequest.h
diff --git a/public/platform/WebURLRequest.h b/public/platform/WebURLRequest.h
index 86a7b1fe84acf49e1e1a49bb2fc2893e78ce1645..acfe12991ba38d8d60bfe55ed97bdde30be51089 100644
--- a/public/platform/WebURLRequest.h
+++ b/public/platform/WebURLRequest.h
@@ -123,6 +123,12 @@ 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).
@@ -258,6 +264,10 @@ public:
     BLINK_PLATFORM_EXPORT FetchCredentialsMode fetchCredentialsMode() const;
     BLINK_PLATFORM_EXPORT void setFetchCredentialsMode(FetchCredentialsMode);
 
+    // The redirect mode which is used in Fetch API.
+    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