Fetch API: Add Request#cache attribute

third_party/WebKit/Source/modules/fetch/Request.idl

Index: third_party/WebKit/Source/modules/fetch/Request.idl
diff --git a/third_party/WebKit/Source/modules/fetch/Request.idl b/third_party/WebKit/Source/modules/fetch/Request.idl
index c227d390ea1cd40a1011a95c5dfc33d6affb891d..b5fac68043b7145a63f376a2b8cbf7a131e802c3 100644
--- a/third_party/WebKit/Source/modules/fetch/Request.idl
+++ b/third_party/WebKit/Source/modules/fetch/Request.idl
@@ -9,6 +9,8 @@ typedef (Request or USVString) RequestInfo;
 enum RequestMode { "navigate", "same-origin", "no-cors", "cors" };
 enum RequestCredentials { "omit", "same-origin", "include" };
 enum RequestRedirect { "follow", "error", "manual" };
+enum RequestCache { "default", "no-store", "reload", "no-cache", "force-cache", 
+    "only-if-cached" };
 
 // https://w3c.github.io/webappsec-referrer-policy/#referrer-policies
 
@@ -36,6 +38,7 @@ enum ReferrerPolicy {
     [ImplementedAs=getReferrerPolicy] readonly attribute ReferrerPolicy referrerPolicy;
     readonly attribute RequestMode mode;
     readonly attribute RequestCredentials credentials;
+    [RuntimeEnabled=FetchRequestCache]readonly attribute RequestCache cache;
     readonly attribute RequestRedirect redirect;
     readonly attribute DOMString integrity;