Fix race condition in gamepad that prevents it to work without a rAF loop

content/renderer/gamepad_shared_memory_reader.cc

 // Copyright (c) 2012 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.
 
 #include "content/renderer/gamepad_shared_memory_reader.h"
 
 #include "base/debug/trace_event.h"
 #include "base/metrics/histogram.h"
 #include "content/common/gamepad_user_gesture.h"
 #include "content/public/renderer/render_thread.h"
@@ skipping 83 matching lines @@
     // We failed to successfully read, presumably because the hardware
     // thread was taking unusually long. Don't copy the data to the output
     // buffer, and simply leave what was there before.
     return;
   }
 
   // New data was read successfully, copy it into the output buffer.
   memcpy(&gamepads, &read_into, sizeof(gamepads));
 
   if (!ever_interacted_with_) {
-    if (GamepadsHaveUserGesture(gamepads)) {
-      ever_interacted_with_ = true;
-    } else {
-      // Clear the connected flag if the user hasn't interacted with any of the
-      // gamepads to prevent fingerprinting. The actual data is not cleared.
-      // WebKit will only copy out data into the JS buffers for connected
-      // gamepads so this is sufficient.
-      for (unsigned i = 0; i < blink::WebGamepads::itemsLengthCap; i++)
-        gamepads.items[i].connected = false;
-    }
+    // Clear the connected flag if the user hasn't interacted with any of the
+    // gamepads to prevent fingerprinting. The actual data is not cleared.
+    // WebKit will only copy out data into the JS buffers for connected
+    // gamepads so this is sufficient.
+    for (unsigned i = 0; i < blink::WebGamepads::itemsLengthCap; i++)
+      gamepads.items[i].connected = false;
   }
 }
 
 void GamepadSharedMemoryReader::SetGamepadListener(
     blink::WebGamepadListener* listener) {
   gamepad_listener_ = listener;
   if (gamepad_listener_) {
     // Polling has to be started rigth now and not just on the first sampling
     // because want to get connection events from now.
     StartPollingIfNecessary();
@@ skipping 13 matching lines @@
     IPC_MESSAGE_HANDLER(GamepadMsg_GamepadConnected, OnGamepadConnected)
     IPC_MESSAGE_HANDLER(GamepadMsg_GamepadDisconnected, OnGamepadDisconnected)
     IPC_MESSAGE_UNHANDLED(handled = false)
   IPC_END_MESSAGE_MAP()
   return handled;
 }
 
 void GamepadSharedMemoryReader::OnGamepadConnected(
     int index,
     const blink::WebGamepad& gamepad) {
+  // The browser already checks if the user actually interacted with a device.
+  ever_interacted_with_ = true;
+
   if (gamepad_listener_)
     gamepad_listener_->didConnectGamepad(index, gamepad);
 }
 
 void GamepadSharedMemoryReader::OnGamepadDisconnected(
     int index,
     const blink::WebGamepad& gamepad) {
   if (gamepad_listener_)
     gamepad_listener_->didDisconnectGamepad(index, gamepad);
 }
 
 } // namespace content