Reland: Introduce the devices Mojo app

device/core/device_client.cc

Index: device/core/device_client.cc
diff --git a/device/core/device_client.cc b/device/core/device_client.cc
index 2aca21693a2d597898b8565dccd4a2506dc2ff3f..52021221d9f0fc84130109ba6846a7d3eafd0627 100644
--- a/device/core/device_client.cc
+++ b/device/core/device_client.cc
@@ -35,10 +35,6 @@ UsbService* DeviceClient::GetUsbService() {
   return NULL;
 }
 
-void DeviceClient::ConnectToUSBDeviceManager(
-    mojo::InterfaceRequest<usb::DeviceManager> request) {
-}
-
 HidService* DeviceClient::GetHidService() {
   // This should never be called by clients which do not support the HID API.
   NOTREACHED();