Add Mojo structs and StructTraits for //ui/events/devices.

ui/events/devices/mojo/input_device_struct_traits.h

Index: ui/events/devices/mojo/input_device_struct_traits.h
diff --git a/ui/events/devices/mojo/input_device_struct_traits.h b/ui/events/devices/mojo/input_device_struct_traits.h
new file mode 100644
index 0000000000000000000000000000000000000000..d2945bb6ba07c317a3f467d708975b0680c82ff5
--- /dev/null
+++ b/ui/events/devices/mojo/input_device_struct_traits.h
@@ -0,0 +1,113 @@
+// 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.
+
+#ifndef UI_EVENTS_DEVICES_MOJO_INPUT_DEVICE_STRUCT_TRAITS_H_
+#define UI_EVENTS_DEVICES_MOJO_INPUT_DEVICE_STRUCT_TRAITS_H_
+
+#include <string>
+
+#include "base/strings/string_piece.h"
+#include "ui/events/devices/input_device.h"
+#include "ui/events/devices/mojo/input_devices.mojom.h"
+#include "ui/events/devices/touchscreen_device.h"
+#include "ui/gfx/geometry/size.h"
+
+namespace mojo {
+
+template <>
+struct StructTraits<ui::mojom::InputDevice, ui::InputDevice> {
+  static int32_t id(const ui::InputDevice& device) { return device.id; }
+
+  static ui::mojom::InputDeviceType type(const ui::InputDevice& device) {
+    switch (device.type) {
+      case ui::INPUT_DEVICE_INTERNAL:
+        return ui::mojom::InputDeviceType::INPUT_DEVICE_INTERNAL;
+      case ui::INPUT_DEVICE_EXTERNAL:
+        return ui::mojom::InputDeviceType::INPUT_DEVICE_EXTERNAL;
+      case ui::INPUT_DEVICE_UNKNOWN:
+        return ui::mojom::InputDeviceType::INPUT_DEVICE_UNKNOWN;
+    }
+  }
+
+  static const std::string& name(const ui::InputDevice& device) {
+    return device.name;
+  }
+
+  static base::StringPiece sys_path(const ui::InputDevice& device) {
+    return device.sys_path.AsUTF8Unsafe();
+  }
+
+  static uint32_t vendor_id(const ui::InputDevice& device) {
+    return device.vendor_id;
+  }
+
+  static uint32_t product_id(const ui::InputDevice& device) {
+    return device.product_id;
+  }
+
+  static bool Read(ui::mojom::InputDeviceDataView data, ui::InputDevice* out) {
+    out->id = data.id();
+
+    switch (data.type()) {
+      case ui::mojom::InputDeviceType::INPUT_DEVICE_INTERNAL:
+        out->type = ui::INPUT_DEVICE_INTERNAL;
+        break;
+      case ui::mojom::InputDeviceType::INPUT_DEVICE_EXTERNAL:
+        out->type = ui::INPUT_DEVICE_EXTERNAL;
+        break;
+      case ui::mojom::InputDeviceType::INPUT_DEVICE_UNKNOWN:
+        out->type = ui::INPUT_DEVICE_UNKNOWN;
+        break;
+      default:
+        // Who knows what values might come over the wire, fail if invalid.
+        return false;
+    }
+
+    if (!data.ReadName(&out->name))
+      return false;
+
+    base::StringPiece sys_path_string;
+    if (!data.ReadSysPath(&sys_path_string))
+      return false;
+    out->sys_path = base::FilePath::FromUTF8Unsafe(sys_path_string);

[sadrul, 2016/06/09 14:21:45]

Should we be using FromUTF8Unsafe() on something we are receiving from a remote
client?

[kylechar, 2016/06/09 14:42:14]

My understanding is that the decoding/encoding of the filepath internal
representation to UTF8 might be unsafe (aka it could mangle the path depending
on filesystem locale). The path is just compared against in
ash::GetUdlAssociationScore(), it's never opened, so there is little to no risk
I think?

The comments in FilePath indicate there is no perfect way to encode a FilePath
to a string and that the choices are ASCII, UTF8 or UTF16. UTF8 seems right to
me?

[sadrul, 2016/06/09 15:09:19]

For now, yeah. It'd be difficult to restrict how it's used in the future though.

I wanted to make sure we didn't accidentally overlook this. But as long as sec.
folks are happy, I am happy. lgtm

+
+    out->vendor_id = data.vendor_id();
+    out->product_id = data.product_id();
+
+    return true;
+  }
+};
+
+template <>
+struct StructTraits<ui::mojom::TouchscreenDevice, ui::TouchscreenDevice> {
+  static const ui::InputDevice& input_device(
+      const ui::TouchscreenDevice& device) {
+    return static_cast<const ui::InputDevice&>(device);
+  }
+
+  static const gfx::Size& size(const ui::TouchscreenDevice& device) {
+    return device.size;
+  }
+
+  static int32_t touch_points(const ui::TouchscreenDevice& device) {
+    return device.touch_points;
+  }
+
+  static bool 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
+
+#endif  // UI_EVENTS_DEVICES_MOJO_INPUT_DEVICE_STRUCT_TRAITS_H_