Add timeout task to U2F HID state machine

device/u2f/u2f_hid_device.h

Index: device/u2f/u2f_hid_device.h
diff --git a/device/u2f/u2f_hid_device.h b/device/u2f/u2f_hid_device.h
index 527c0b30177d73554b328c108745ee2abbe4c3ad..eaa2f37f0967fb8ae6d31123245bbbd8dfebee6e 100644
--- a/device/u2f/u2f_hid_device.h
+++ b/device/u2f/u2f_hid_device.h
@@ -7,6 +7,7 @@
 
 #include <list>
 
+#include "base/cancelable_callback.h"
 #include "device/hid/hid_service.h"
 #include "u2f_device.h"
 
@@ -23,7 +24,7 @@ class HidDeviceInfo;
 class U2fHidDevice : public U2fDevice {
  public:
   U2fHidDevice(scoped_refptr<HidDeviceInfo>);
-  ~U2fHidDevice();
+  ~U2fHidDevice() final;
 
   // Send a U2f command to this device
   void DeviceTransact(std::unique_ptr<U2fApduCommand> command,
@@ -70,7 +71,7 @@ class U2fHidDevice : public U2fDevice {
                      bool success);
   // Read all response message packets from device
   void ReadMessage(U2fHidMessageCallback callback);
-  void MessageReceived(const DeviceCallback& callback,
+  void MessageReceived(DeviceCallback callback,

[Reilly Grant (use Gerrit), 2017/04/17 22:25:17]

DeviceCallback is not a OnceCallback so it should be passed by const& here and
below.

[Casey Piper, 2017/04/17 23:02:38]

Done.

                        bool success,
                        std::unique_ptr<U2fMessage> message);
   void OnRead(U2fHidMessageCallback callback,
@@ -85,8 +86,12 @@ class U2fHidDevice : public U2fDevice {
   void OnWink(const WinkCallback& callback,
               bool success,
               std::unique_ptr<U2fMessage> response);
+  void OnTimeout(DeviceCallback callback);
+  void OnDeviceTransact(bool success,
+                        std::unique_ptr<U2fApduResponse> response);
 
   State state_;
+  base::CancelableClosure timeout_callback_;
   std::list<std::pair<std::unique_ptr<U2fApduCommand>, DeviceCallback>>
       pending_transactions_;
   scoped_refptr<HidDeviceInfo> device_info_;