Gamepad: add test support for page visibility behavior

content/public/renderer/renderer_gamepad_provider.h

+// Copyright (c) 2014 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_GAMEPAD_RENDERER_PROVIDER_H_
+#define CONTENT_GAMEPAD_RENDERER_PROVIDER_H_
+
+namespace blink {
+class WebGamepadListener;
+class WebGamepads;
+}
+
+namespace content {
+
+// Provides gamepad data and events for blink.
+class RendererGamepadProvider {
+ public:
+  // Provides latest snapshot of gamepads.
+  virtual void SampleGamepads(blink::WebGamepads& gamepads) = 0;
+
+  // Registers listener for be notified of events.
+  virtual void SetGamepadListener(blink::WebGamepadListener* listener) = 0;
+
+ protected:
+  virtual ~RendererGamepadProvider() {}
+};
+
+} // namespace content
+
+#endif