Add more generic filters to the chrome.hid.getDevices API.

extensions/common/api/hid.idl

 // Copyright 2014 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.
 
 // Use the <code>chrome.hid</code> API to interact with connected HID devices.
 // This API provides access to HID operations from within the context of an app.
 // Using this API, apps can function as drivers for hardware devices.
 namespace hid {
   // HID top-level collection attributes.
   // Each enumerated device interface exposes an array of these objects.
@@ skipping 24 matching lines @@
     long maxOutputReportSize;
     long maxFeatureReportSize;
   };
 
   // Returned by <code>connect</code> to represent a communication session with
   // an HID device. Must be closed with a call to <code>disconnect</code>.
   dictionary HidConnectInfo {
     long connectionId;
   };
 
-  // Searching criteria to enumerate devices with.
+  // Device matching criteria.
+  dictionary HidDeviceFilter {
+    long? vendorId;
+    long? productId;
+    long? usagePage;
+    long? usage;
+  };
+
+  // Options passed to <code>getDevices</code>.
   dictionary GetDevicesOptions {
-    long vendorId;
-    long productId;
+    long? vendorId;
+    long? productId;
+    HidDeviceFilter[]? filters;

[not at google - send to devlin, 2014/08/28 23:12:08]

Are you leaving |vendorId| and |productId| in this structure for backwards
compatibility? Since they could be modelled as a filter, right?

[Reilly Grant (use Gerrit), 2014/08/28 23:13:09]

Yes, the implementation creates a filter to model them if they are given.

[not at google - send to devlin, 2014/08/28 23:18:36]

It's a shame to see the HID API reach this far and then have this change made
just for backwards compatibility. Should you be deprecating the old properties?

Also: please document everything you've added here.

   };
 
   callback GetDevicesCallback = void (HidDeviceInfo[] devices);
   callback ConnectCallback = void (HidConnectInfo connection);
   callback DisconnectCallback = void ();
 
   // The callback to be invoked when a <code>receive</code> call is finished.
   // |reportId|: The ID of the report.
   // |data|: The content of the report.
   callback ReceiveCallback = void (long reportId, ArrayBuffer data);
@@ skipping 66 matching lines @@
     // |connectionId|: The connection to read Input report from.
     // |reportId|: The report ID to use, or <code>0</code> if none.
     // |data|: The report data.
     // |callback|: The callback to invoke once the write is finished.
     static void sendFeatureReport(long connectionId,
                                   long reportId,
                                   ArrayBuffer data,
                                   SendCallback callback);
   };
 };