Add gamepad data fetcher for Linux

content/browser/gamepad/gamepad_standard_mappings_linux.h

Index: content/browser/gamepad/gamepad_standard_mappings_linux.h
diff --git a/content/browser/gamepad/gamepad_standard_mappings_linux.h b/content/browser/gamepad/gamepad_standard_mappings_linux.h
new file mode 100644
index 0000000000000000000000000000000000000000..59e937118d13d41078fe3c7bf3b3b4eb54ba051b
--- /dev/null
+++ b/content/browser/gamepad/gamepad_standard_mappings_linux.h
@@ -0,0 +1,26 @@
+// 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_GAMEPAD_STANDARD_MAPPINGS_LINUX_H_
+#define CONTENT_BROWSER_GAMEPAD_GAMEPAD_STANDARD_MAPPINGS_LINUX_H_
+
+#include "base/string_piece.h"
+
+namespace WebKit {
+class WebGamepad;
+}
+
+namespace content {
+
+typedef void (*GamepadStandardMappingFunction)(
+    const WebKit::WebGamepad& original,
+    WebKit::WebGamepad* mapped);
+
+GamepadStandardMappingFunction GetGamepadStandardMappingFunction(
+    const base::StringPiece& vendor_id,
+    const base::StringPiece& product_id);
+
+}  // namespace content
+
+#endif  // CONTENT_BROWSER_GAMEPAD_GAMEPAD_STANDARD_MAPPINGS_LINUX_H_