Add gamepad data fetcher for Linux

content/browser/gamepad/data_fetcher_mac.h

-// Copyright (c) 2011 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 CONTENT_BROWSER_GAMEPAD_DATA_FETCHER_MAC_H_
-#define CONTENT_BROWSER_GAMEPAD_DATA_FETCHER_MAC_H_
-
-#include "build/build_config.h"
-
-#include "base/compiler_specific.h"
-#include "base/mac/scoped_cftyperef.h"
-#include "content/browser/gamepad/data_fetcher.h"
-#include "content/common/gamepad_hardware_buffer.h"
-
-#include <CoreFoundation/CoreFoundation.h>
-#include <IOKit/hid/IOHIDManager.h>
-
-#if defined(__OBJC__)
-@class NSArray;
-#else
-class NSArray;
-#endif
-
-namespace content {
-
-class GamepadDataFetcherMac : public GamepadDataFetcher {
- public:
-  GamepadDataFetcherMac();
-  virtual ~GamepadDataFetcherMac();
-  virtual void GetGamepadData(WebKit::WebGamepads* pads,
-                              bool devices_changed_hint) OVERRIDE;
-  virtual void PauseHint(bool paused) OVERRIDE;
- private:
-  bool enabled_;
-  base::mac::ScopedCFTypeRef<IOHIDManagerRef> hid_manager_ref_;
-
-  static GamepadDataFetcherMac* InstanceFromContext(void* context);
-  static void DeviceAddCallback(void* context,
-                                IOReturn result,
-                                void* sender,
-                                IOHIDDeviceRef ref);
-  static void DeviceRemoveCallback(void* context,
-                                   IOReturn result,
-                                   void* sender,
-                                   IOHIDDeviceRef ref);
-  static void ValueChangedCallback(void* context,
-                                   IOReturn result,
-                                   void* sender,
-                                   IOHIDValueRef ref);
-
-  void DeviceAdd(IOHIDDeviceRef device);
-  void AddButtonsAndAxes(NSArray* elements, size_t slot);
-  void DeviceRemove(IOHIDDeviceRef device);
-  void ValueChanged(IOHIDValueRef value);
-
-  void RegisterForNotifications();
-  void UnregisterFromNotifications();
-
-  WebKit::WebGamepads data_;
-
-  // Side-band data that's not passed to the consumer, but we need to maintain
-  // to update data_.
-  struct AssociatedData {
-    IOHIDDeviceRef device_ref;
-    IOHIDElementRef button_elements[WebKit::WebGamepad::buttonsLengthCap];
-    IOHIDElementRef axis_elements[WebKit::WebGamepad::buttonsLengthCap];
-    CFIndex axis_minimums[WebKit::WebGamepad::axesLengthCap];
-    CFIndex axis_maximums[WebKit::WebGamepad::axesLengthCap];
-  };
-  AssociatedData associated_[WebKit::WebGamepads::itemsLengthCap];
-};
-
-}  // namespace content
-
-#endif  // CONTENT_BROWSER_GAMEPAD_DATA_FETCHER_MAC_H_