[ios] Adds code to support the iOS Handoff feature.

components/handoff/pref_names_ios.cc

Index: components/handoff/pref_names_ios.cc
diff --git a/components/handoff/pref_names_ios.cc b/components/handoff/pref_names_ios.cc
new file mode 100644
index 0000000000000000000000000000000000000000..2a7f166734a851881bce163247f34f23c209fd3a
--- /dev/null
+++ b/components/handoff/pref_names_ios.cc
@@ -0,0 +1,13 @@
+// Copyright 2016 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.
+
+#import "components/handoff/pref_names_ios.h"
+
+namespace prefs {
+
+// Whether Chrome should attempt to hand off the current URL to other Apple
+// devices that share an iCloud account.
+const char kIosHandoffToOtherDevices[] = "ios.handoff_to_other_devices";
+
+}  // namespace prefs