Add FrameHost mojo service

content/common/host_zoom_level.mojom

Index: content/common/host_zoom_level.mojom
diff --git a/url/mojo/url_test.mojom b/content/common/host_zoom_level.mojom
similarity index 54%
copy from url/mojo/url_test.mojom
copy to content/common/host_zoom_level.mojom
index c9b346988f546008a0cfb10d94887f67aa0c8550..f1bc0a179d865e698cf84c28d6dda9eda9f634c6 100644
--- a/url/mojo/url_test.mojom
+++ b/content/common/host_zoom_level.mojom
@@ -2,15 +2,11 @@
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
-module url.mojom;
+module content.mojom;
 
-import "url/mojo/origin.mojom";
 import "url/mojo/url.mojom";
 
-interface UrlTest {
-  [Sync]
-  BounceUrl(Url in) => (Url out);
-
-  [Sync]
-  BounceOrigin(Origin in) => (Origin out);
+interface HostZoomLevel {
+  GetZoomLevel(url.mojom.Url url, int32 render_view_id)

[jam, 2016/05/16 18:28:32]

we eventually want to get rid of routing IDs. 

Can we make this service per-frame instead of per-process? then we don't need to
pass routing IDs.

[wjmaclean, 2016/05/16 18:59:53]

Sorry, just noticed this comment.

The main concern here I think is whether the zoom level is based on the URL as
stored in the HostZoomMap, or to a view/page in which the normal zoom level is
overriden (TemporaryZoomLevel). In either case I think it's fine to think of the
zoom level as being tied to the frame, since any frame will be tied to a
particular view from which a zoom level can be found. If the frame is top-level,
then its preferred zoom level is dictated by that of the main frame anyways.

[scottmg, 2016/05/16 22:54:56]

OK, thanks. Moved to the frame.

+      => (url.mojom.Url url, double zoom_level);
 };