Expose Gamepad API instance for Cardboard button

device/vr/android/gvr/cardboard_gamepad_data_fetcher.h

Index: device/vr/android/gvr/cardboard_gamepad_data_fetcher.h
diff --git a/device/vr/android/gvr/cardboard_gamepad_data_fetcher.h b/device/vr/android/gvr/cardboard_gamepad_data_fetcher.h
new file mode 100644
index 0000000000000000000000000000000000000000..0b6193faf8dd74e882606493a010230f443f2374
--- /dev/null
+++ b/device/vr/android/gvr/cardboard_gamepad_data_fetcher.h
@@ -0,0 +1,51 @@
+// 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_CARDBOARD_GAMEPAD_DATA_FETCHER_H_
+#define DEVICE_VR_ANDROID_CARDBOARD_GAMEPAD_DATA_FETCHER_H_
+
+#include <string>
+
+#include "device/gamepad/gamepad_data_fetcher.h"
+#include "device/vr/android/gvr/cardboard_gamepad_data_provider.h"
+#include "device/vr/vr_export.h"
+
+namespace device {
+
+class DEVICE_VR_EXPORT CardboardGamepadDataFetcher : public GamepadDataFetcher {
+ public:
+  class Factory : public GamepadDataFetcherFactory {
+   public:
+    Factory(CardboardGamepadDataProvider*, unsigned int display_id);
+    ~Factory() override;
+    std::unique_ptr<GamepadDataFetcher> CreateDataFetcher() override;
+    GamepadSource source() override;
+
+   private:
+    CardboardGamepadDataProvider* data_provider_;
+    unsigned int display_id_;
+  };
+
+  CardboardGamepadDataFetcher(CardboardGamepadDataProvider*,
+                              unsigned int display_id);
+  ~CardboardGamepadDataFetcher() override;
+
+  GamepadSource source() override;
+
+  void GetGamepadData(bool devices_changed_hint) override;
+  void PauseHint(bool paused) override;
+  void OnAddedToProvider() override;
+
+  // Called from CardboardGamepadDataProvider
+  void SetGamepadData(CardboardGamepadData);
+
+ private:
+  unsigned int display_id_;
+  CardboardGamepadData gamepad_data_;
+
+  DISALLOW_COPY_AND_ASSIGN(CardboardGamepadDataFetcher);
+};
+
+}  // namespace device
+#endif  // DEVICE_VR_ANDROID_CARDBOARD_GAMEPAD_DATA_FETCHER_H_