Add tests for InputDevice/TouchscreenDevice StructTraits.

ui/events/devices/mojo/input_device_struct_traits.cc

 // Copyright 2016 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.
 
 #include "ui/events/devices/mojo/input_device_struct_traits.h"
 
 #include "base/logging.h"
 #include "ui/gfx/geometry/mojo/geometry_struct_traits.h"
 
 namespace mojo {
@@ skipping 37 matching lines @@
     ui::mojom::InputDeviceDataView data,
     ui::InputDevice* out) {
   out->id = data.id();
 
   if (!data.ReadType(&out->type))
     return false;
 
   if (!data.ReadName(&out->name))
     return false;
 
-  base::StringPiece sys_path_string;
+  std::string sys_path_string;
   if (!data.ReadSysPath(&sys_path_string))
     return false;
   out->sys_path = base::FilePath::FromUTF8Unsafe(sys_path_string);
 
   out->vendor_id = data.vendor_id();
   out->product_id = data.product_id();
 
   return true;
 }
 
 bool StructTraits<ui::mojom::TouchscreenDevice, ui::TouchscreenDevice>::Read(
     ui::mojom::TouchscreenDeviceDataView data,
     ui::TouchscreenDevice* out) {
   if (!data.ReadInputDevice(static_cast<ui::InputDevice*>(out)))
     return false;
 
   if (!data.ReadSize(&out->size))
     return false;
 
   out->touch_points = data.touch_points();
 
   return true;
 }
 
 }  // namespace mojo