Add mojo struct traits for GURL so that it can be sent over mojoms.

url/mojo/url.mojom

Index: url/mojo/url.mojom
diff --git a/gpu/command_buffer/common/capabilities.mojom b/url/mojo/url.mojom
similarity index 77%
copy from gpu/command_buffer/common/capabilities.mojom
copy to url/mojo/url.mojom
index fd35409e940e193377d9411c182e99746220f2a7..610bde0656369bafc808d7225be19eec1801d8bf 100644
--- a/gpu/command_buffer/common/capabilities.mojom
+++ b/url/mojo/url.mojom
@@ -1,8 +1,9 @@
-// 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.
-
-module gpu.mojom;
-
-[Native]
-struct Capabilities;
+// 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.
+
+module url;

[Ken Rockot(use gerrit already), 2016/03/03 05:23:28]

I think this is fine as is, but IMHO we should really be consistent with mojom
namespaces (i know, i know). I also think if we do that, the outer namespace
should match between the mojom type and the typemapped type. So because in this
case GURL is in the global namespace, I would argue this should just be module
mojom.

I would also personally prefer URL over Url, but I see that's against style
guide recommendations...

[jam, 2016/03/03 16:09:04]

ah I forgot, added mojom.
GURL is in global namespace because it's before we had the convention of code in
src\foo should be in foo namespace, and no one bothered to update it.
ditto

+
+struct Url {
+  string url;
+};