Fetch: Fix 'body' processing in RequestInit.

third_party/WebKit/LayoutTests/http/tests/fetch/script-tests/request.js

Index: third_party/WebKit/LayoutTests/http/tests/fetch/script-tests/request.js
diff --git a/third_party/WebKit/LayoutTests/http/tests/fetch/script-tests/request.js b/third_party/WebKit/LayoutTests/http/tests/fetch/script-tests/request.js
index af33bce4cc61156593d57161c97e7197ed9be4c8..2295db08e135922c42f533e3bddf531bb557a85c 100644
--- a/third_party/WebKit/LayoutTests/http/tests/fetch/script-tests/request.js
+++ b/third_party/WebKit/LayoutTests/http/tests/fetch/script-tests/request.js
@@ -748,4 +748,16 @@ promise_test(function(t) {
         });
   }, 'Extract a MIME type (1)');
 
+promise_test(function(t) {
+    var req = new Request('http://localhost/',
+                          {method: 'POST',
+                           credentials: 'include',
+                           body: 'this is a body'});
+
+    return req.text()
+        .then(t => {
+           assert_equals(t, 'this is a body');
+        });
+  }, 'Credentials and body can both be set.');
+
 done();