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..3b55ebbaa7169e91fbb9546bcc74076d58894cd9 100644
--- a/third_party/WebKit/Source/modules/fetch/Request.cpp
+++ b/third_party/WebKit/Source/modules/fetch/Request.cpp
@@ -162,9 +162,14 @@ Request* Request::createRequestWithRequestOrString(ScriptState* scriptState, Req
     }
 
 
-    // "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") {
@@ -490,6 +495,8 @@ String Request::mode() const
     // "The mode attribute's getter must return the value corresponding to the
     // first matching statement, switching on request's mode:"
     switch (m_request->mode()) {
+    case WebURLRequest::FetchRequestModeNavigate:
+        return "navigate";
     case WebURLRequest::FetchRequestModeSameOrigin:
         return "same-origin";
     case WebURLRequest::FetchRequestModeNoCORS: