Add navigation client lib for convenience

services/navigation/public/cpp/BUILD.gn

Index: services/navigation/public/cpp/BUILD.gn
diff --git a/services/navigation/public/cpp/BUILD.gn b/services/navigation/public/cpp/BUILD.gn
new file mode 100644
index 0000000000000000000000000000000000000000..4b1b87861e30475e11ba74f13e82d30fd65368bf
--- /dev/null
+++ b/services/navigation/public/cpp/BUILD.gn
@@ -0,0 +1,18 @@
+# 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.
+
+source_set("cpp") {
+  sources = [
+    "view.cc",
+    "view.h",
+    "view_delegate.h",
+  ]
+
+  deps = [
+    "//base",
+    "//mojo/public/cpp/bindings",
+    "//services/navigation/public/interfaces",
+    "//url",
+  ]
+}