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

extensions/common/api/hid.idl

Index: extensions/common/api/hid.idl
diff --git a/extensions/common/api/hid.idl b/extensions/common/api/hid.idl
index c6bb316311968db0d462bea3e9e8464635854e3a..11ee6b97b48a6cd1e74ae4c586703b447ad0a594 100644
--- a/extensions/common/api/hid.idl
+++ b/extensions/common/api/hid.idl
@@ -42,10 +42,19 @@ namespace hid {
     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);