Update Background Fetch IDLs following spec changes

third_party/WebKit/Source/modules/background_fetch/BackgroundFetchSettledFetch.cpp

Index: third_party/WebKit/Source/modules/background_fetch/BackgroundFetchSettledFetch.cpp
diff --git a/third_party/WebKit/Source/modules/background_fetch/BackgroundFetchSettledFetch.cpp b/third_party/WebKit/Source/modules/background_fetch/BackgroundFetchSettledFetch.cpp
new file mode 100644
index 0000000000000000000000000000000000000000..6a2f32eac86868123bae372e9afd12ff2ff8632b
--- /dev/null
+++ b/third_party/WebKit/Source/modules/background_fetch/BackgroundFetchSettledFetch.cpp
@@ -0,0 +1,24 @@
+// Copyright 2017 The Chromium Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+#include "modules/background_fetch/BackgroundFetchSettledFetch.h"
+
+#include "modules/fetch/Response.h"
+
+namespace blink {
+
+BackgroundFetchSettledFetch::BackgroundFetchSettledFetch(Request* request,
+                                                         Response* response)
+    : BackgroundFetchFetch(request), m_response(response) {}
+
+Response* BackgroundFetchSettledFetch::response() const {
+  return m_response;
+}
+
+DEFINE_TRACE(BackgroundFetchSettledFetch) {
+  visitor->trace(m_response);
+  BackgroundFetchFetch::trace(visitor);
+}
+
+}  // namespace blink