Add support of Pause/Resume for polling thread

Source/modules/gamepad/NavigatorGamepad.cpp

 /*
  * Copyright (C) 2011, Google Inc. All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions are met:
  *
  * 1. Redistributions of source code must retain the above copyright
  *    notice, this list of conditions and the following disclaimer.
  * 2. Redistributions in binary form must reproduce the above copyright
  *    notice, this list of conditions and the following disclaimer in the
@@ skipping 41 matching lines @@
             gamepad->buttons(webGamepad.buttonsLength, webGamepad.buttons);
             into->set(i, gamepad);
         } else {
             into->set(i, 0);
         }
     }
 }
 
 NavigatorGamepad::NavigatorGamepad()
 {
+    blink::Platform::current()->resumeGamepads();
 }
 
 NavigatorGamepad::~NavigatorGamepad()
 {
+    blink::Platform::current()->pauseGamepads();

[scottmg, 2014/02/06 20:46:23]

I don't think the renderer should be telling the browser when to do this. If the
renderer crashes, then these will be unbalanced.

 }
 
 const char* NavigatorGamepad::supplementName()
 {
     return "NavigatorGamepad";
 }
 
 NavigatorGamepad* NavigatorGamepad::from(Navigator* navigator)
 {
     NavigatorGamepad* supplement = static_cast<NavigatorGamepad*>(Supplement<Navigator>::from(navigator, supplementName()));
@@ skipping 11 matching lines @@
 
 GamepadList* NavigatorGamepad::gamepads()
 {
     if (!m_gamepads)
         m_gamepads = GamepadList::create();
     sampleGamepads(m_gamepads.get());
     return m_gamepads.get();
 }
 
 } // namespace WebCore