Introduce "navigate" mode in Requests

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

Index: third_party/WebKit/Source/modules/fetch/Request.cpp
diff --git a/third_party/WebKit/Source/modules/fetch/Request.cpp b/third_party/WebKit/Source/modules/fetch/Request.cpp
index 6cc792b88301ee34dc12b0111f299471192655fa..8c1fd8a33553ee18bd4c05348367624d7910b88f 100644
--- a/third_party/WebKit/Source/modules/fetch/Request.cpp
+++ b/third_party/WebKit/Source/modules/fetch/Request.cpp
@@ -120,15 +120,23 @@ Request* Request::createRequestWithRequestOrString(ScriptState* scriptState, Req
         // We don't use fallback values. We set these flags directly in below.
     }
 
-    //   14. If any of |init|'s members are present, set |request|'s referrer
-    // to client, and |request|'s referrer policy to the empty string.
-    //   => RequestInit::RequestInit.
+    // "14. If any of |init|'s members are present, run these substeps:"
+    if (init.areAnyMembersSet) {
+        // "1. If request's |mode| is "navigate", throw a TypeError."
+        if (request->mode() == WebURLRequest::FetchRequestModeNavigate) {
+            exceptionState.throwTypeError("Cannot construct a Request with a Request mode as navigate.");
+            return nullptr;
+        }
+    }
+
     //   15. If |init|'s referrer member is present, run these substeps:
     // Note that JS null and undefined are encoded as an empty string and thus
     // a null string means referrer member is not set.
     //   16. If |init|'s referrerPolicy member is present, set |request|'s
     // referrer policy to it.
-    if (init.isReferrerSet) {
+    // areAnyMembersSet will be True, if any members in RequestInit are set and
+    // hence the referrer member

[Mike West, 2015/10/20 07:27:04]

Nit: hence the referrer member what?

[shiva.jm, 2015/10/21 08:34:59]

actually below condition is checking, 
If |init|'s referrer member is present, since we have
renamed earlier used 'isReferrerSet' --> 'areAnyMembersSet',
so added above comments, so that user will not have confusion.
also if, 'areAnyMembersSet' is true means, any of RequestInit members are set,
which might include referrer member as well. as discussed in comments:
https://codereview.chromium.org/1391583002/#msg14

+    if (init.areAnyMembersSet) {
         // 1. Let |referrer| be |init|'s referrer member.
         if (init.referrer.referrer.isEmpty()) {
             // 2. if |referrer| is the empty string, set |request|'s referrer to
@@ -161,10 +169,14 @@ Request* Request::createRequestWithRequestOrString(ScriptState* scriptState, Req
         request->setReferrerPolicy(init.referrer.referrerPolicy);
     }
 
-
-    // "17. Let |mode| be |init|'s mode member if it is present, and
+    // "16. Let |mode| be |init|'s mode member if it is present, and
     // |fallbackMode| otherwise."
+    // "17.If mode is "navigate", throw a TypeError.
     // "18. If |mode| is non-null, set |request|'s mode to |mode|."
+    if (init.mode == "navigate") {
+        exceptionState.throwTypeError("Cannot construct a Request with a Request mode as navigate.");
+        return nullptr;
+    }
     if (init.mode == "same-origin") {
         request->setMode(WebURLRequest::FetchRequestModeSameOrigin);
     } else if (init.mode == "no-cors") {
@@ -497,6 +509,8 @@ String Request::mode() const
     case WebURLRequest::FetchRequestModeCORS:
     case WebURLRequest::FetchRequestModeCORSWithForcedPreflight:
         return "cors";
+    case WebURLRequest::FetchRequestModeNavigate:
+        return "navigate";
     }
     ASSERT_NOT_REACHED();
     return "";