Fix type truncation warnings in HID code.

device/hid/hid_connection_linux.cc

Index: device/hid/hid_connection_linux.cc
diff --git a/device/hid/hid_connection_linux.cc b/device/hid/hid_connection_linux.cc
index 021d301117b8c303198599f089d5d907dbecdb6f..907f79b769fc4eff51fe021f2ce945642fd0704d 100644
--- a/device/hid/hid_connection_linux.cc
+++ b/device/hid/hid_connection_linux.cc
@@ -111,7 +111,7 @@ void HidConnectionLinux::PlatformGetFeatureReport(
     const ReadCallback& callback) {
   // The first byte of the destination buffer is the report ID being requested
   // and is overwritten by the feature report.
-  DCHECK_GT(device_info().max_feature_report_size, 0);
+  DCHECK_GT(device_info().max_feature_report_size, 0u);
   scoped_refptr<net::IOBufferWithSize> buffer(
       new net::IOBufferWithSize(device_info().max_feature_report_size + 1));
   buffer->data()[0] = report_id;