Refactor GVR controller gamepad API integration

device/vr/android/gvr/gvr_gamepad_data_provider.h

+// Copyright 2017 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 DEVICE_VR_ANDROID_GVR_GAMEPAD_DATA_PROVIDER_H
+#define DEVICE_VR_ANDROID_GVR_GAMEPAD_DATA_PROVIDER_H
+
+#include "third_party/gvr-android-sdk/src/libraries/headers/vr/gvr/capi/include/gvr_types.h"
+
+namespace device {
+
+// Subset of GVR controller data needed for the gamepad API. Filled in
+// by vr_shell's VrController and consumed by GvrGamepadDataFetcher.
+struct GvrGamepadData {
+  int64_t timestamp;
+  gvr_vec2f touch_pos;
+  gvr_quatf orientation;
+  gvr_vec3f accel;
+  gvr_vec3f gyro;
+  bool is_touching;
+  bool controller_button_pressed;
+  bool right_handed;
+};
+
+// This class exposes GVR controller data to the gamepad API. Data is
+// polled by VrShellGl, then posted to VrShell which implements the
+// GvrGamepadDataProvider interface.
+class GvrGamepadDataProvider {
+ public:
+  // Refresh current GVR controller data for use by gamepad API. The
+  // implementation also lazily creates and registers the GVR
+  // GamepadDataFetcherFactory with the GamepadDataFetcherManager as
+  // needed.
+  virtual void GamepadDataUpdate(GvrGamepadData data) = 0;

[mthiesse, 2017/03/21 17:35:13]

nit: Update/GetGamepadData? GamepadDataGet is strange phrasing...

Alternatively OnGamepadDataUpdate(GvrGamepadData data) = 0;

[klausw, 2017/03/21 18:28:55]

Renamed both to put the verb first. I don't like OnGamepadDataUpdate as much
since it's more of an active state change than an event handler, but let me know
if you'd strongly prefer that.

+
+  // Called by the gamepad data fetcher to retrieve the latest snapshot
+  // of controller data.
+  virtual GvrGamepadData GamepadDataGet() = 0;
+};
+
+}  // namespace device
+#endif  // DEVICE_VR_ANDROID_GVR_GAMEPAD_DATA_PROVIDER_H