[Media Router] Use TimeDelta in mojo interfaces

chrome/browser/media/router/mojo/media_router.mojom

 // Copyright 2015 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 media_router.mojom;
 
+import "mojo/common/common_custom_types.mojom";
+
 // Represents an output sink to which media can be routed.
 struct MediaSink {
   enum IconType {
     CAST,
     CAST_AUDIO,
     CAST_AUDIO_GROUP,
     GENERIC,
     HANGOUT
   };
 
@@ skipping 126 matching lines @@
   // Creates a media route from |media_source| to the sink given by |sink_id|.
   //
   // The presentation ID of the route created will be |presentation_id|, but it
   // may be overridden by a provider implementation. The presentation ID will
   // be used by the presentation API to refer to the created route.
   //
   // |origin| and |tab_id| may be passed in for enforcing same-origin and/or
   // same-tab scopes. Use -1 as |tab_id| in cases where the request is not
   // made on behalf of a tab.
   //
-  // If |timeout_millis| is positive, it will be used in place of the default
-  // timeout defined by Media Route Provider Manager.
+  // If |timeout| is positive, it will be used in place of the default timeout
+  // defined by Media Route Provider Manager.
   //
   // If |incognito| is true, the request was made by an incognito profile.
   //
   // If the operation was successful, |route| will be defined and
   //     |error_text| will be null.
   // If the operation failed, |route| will be null and |error_text|
   //     will be set.
   // |result| will be set to OK if successful, or an error code if an error
   // occurred.
   CreateRoute(string media_source,
               string sink_id,
               string original_presentation_id,
               string origin,
               int32 tab_id,
-              int64 timeout_millis,
+              mojo.common.mojom.TimeDelta timeout,

[miu, 2016/09/10 00:40:17]

OOC, why not use base::TimeDelta instead (here and throughout)? IMHO, would be
much more readable.

[btolsch, 2016/09/10 00:51:39]

I'm not sure I understand the question but I'll try to give some reasoning. 
Even when using typemaps, the mojo interface needs to use mojo types;
base::TimeDelta is only known to c++.  TimeDelta was formerly declared a
[Native] struct so that there was no additional implementation needed for mojo
to use it (uses existing ipc::ParamTraits and member definition), but this only
works while in c++.  Since the extension bindings (javascript) need this type,
it needs to be a proper mojo struct.

[miu, 2016/09/10 23:25:40]

Whoops! My mistake. Thought I was looking at the C++ header
(media_router_mojo_impl.h). Never mind. ;-)

               bool incognito) =>
                   (MediaRoute? route,
                    string? error_text,
                    RouteRequestResultCode result_code);
 
   // Requests a connection to an established route for |media_source| given
   // by |presentation_id|.
   //
   // |origin| and |tab_id| are used for validating same-origin/tab scopes;
   // see CreateRoute for additional documentation.
   //
-  // If |timeout_millis| is positive, it will be used in place of the default
-  // timeout defined by Media Route Provider Manager.
+  // If |timeout| is positive, it will be used in place of the default timeout
+  // defined by Media Route Provider Manager.
   //
   // If the route request was created by an incognito profile,
   // |incognito| must be true.
   //
   // If the operation was successful, |route| will be defined and
   //     |error_text| will be null.
   // If the operation failed, |route| will be null and |error_text|
   //     will be set.
   // |result| will be set to OK if successful, or an error code if an error
   // occurred.
   JoinRoute(string media_source,
             string presentation_id,
             string origin,
             int32 tab_id,
-            int64 timeout_millis,
+            mojo.common.mojom.TimeDelta timeout,
             bool incognito) =>
                 (MediaRoute? route,
                  string? error_text,
                  RouteRequestResultCode result_code);
 
   // Creates a new route for |media_source| that connects to the established
   // route given by |route_id|.
   //
   // The presentation ID of the new route will be |presentation_id|, but it may
   // be overridden by a provider implementation.  The presentation ID will be
   // used by the presentation API to refer to the created route.
   //
   // |origin| and |tab_id| are used for validating same-origin/tab scopes; see
   // CreateRoute for additional documentation.
   //
-  // If |timeout_millis| is positive, it will be used in place of the default
-  // timeout defined by Media Route Provider Manager; see CreateRoute for
-  // additional documentation.
+  // If |timeout| is positive, it will be used in place of the default timeout
+  // defined by Media Route Provider Manager; see CreateRoute for additional
+  // documentation.
   //
   // If the route request was created by an incognito profile,
   // |incognito| must be true.
   //
   // If the operation was successful, |route| will be defined and
   // |error_text| will be null. If the operation failed, |route| will be null
   // and |error_text| will be set.
   //
   // |result| will be set to OK if successful, or an error code if an error
   // occurred.
   ConnectRouteByRouteId(string media_source,
                         string route_id,
                         string presentation_id,
                         string origin,
                         int32 tab_id,
-                        int64 timeout_millis,
+                        mojo.common.mojom.TimeDelta timeout,
                         bool incognito) =>
                             (MediaRoute? route,
                              string? error_text,
                              RouteRequestResultCode result_code);
 
   // Terminates the route specified by |route_id|.  If the route was terminated
   // successfully, |result_code| is set to OK and |error_text| is null.
   // Otherwise, |result_code| is an error code and |error_text| describes the
   // error.
   TerminateRoute(string route_id) =>
@@ skipping 141 matching lines @@
 
   // Called when the a batch of messages arrives from the media sink for the
   // route given by |route_id|.
   // |StartListeningForRouteMessages| must be called first in order to receive
   // messages.
   // |route_id|: ID of route of the messages.
   // |messages|: A non-empty list of messages received.
   OnRouteMessagesReceived(string route_id,
                           array<RouteMessage> messages);
 };