Read HID report descriptor from sysfs and request permission on connect.

device/hid/hid_service.h

Index: device/hid/hid_service.h
diff --git a/device/hid/hid_service.h b/device/hid/hid_service.h
index ea540bbb3b80d4013fc5ff5d8f7e08edad3addbe..a571434e7c400d4fe5f07a39c670875a74f6ae3a 100644
--- a/device/hid/hid_service.h
+++ b/device/hid/hid_service.h
@@ -31,6 +31,13 @@ class HidService {
   // Returns |true| if successful or |false| if |device_id| is invalid.
   bool GetDeviceInfo(const HidDeviceId& device_id, HidDeviceInfo* info) const;
 
+#if defined(OS_CHROMEOS)
+  // Requests access to the given device from the Chrome OS permission broker.
+  virtual void RequestAccess(
+      const HidDeviceId& device_id,
+      const base::Callback<void(bool success)>& callback) = 0;
+#endif
+
   virtual scoped_refptr<HidConnection> Connect(
       const HidDeviceId& device_id) = 0;