Remove task.h and finish base::Bind() migration.

remoting/protocol/jingle_session_unittest.cc

Index: remoting/protocol/jingle_session_unittest.cc
diff --git a/remoting/protocol/jingle_session_unittest.cc b/remoting/protocol/jingle_session_unittest.cc
index d7f2149eeb546c10ae0523b03d5d5600c074a078..ca78e9a44e70fbc3550c1a096aea1e99fc1ee9cb 100644
--- a/remoting/protocol/jingle_session_unittest.cc
+++ b/remoting/protocol/jingle_session_unittest.cc
@@ -3,6 +3,7 @@
 // found in the LICENSE file.
 
 #include "base/bind.h"
+#include "base/bind_helpers.h"
 #include "base/message_loop_proxy.h"
 #include "base/time.h"
 #include "net/socket/socket.h"
@@ -262,8 +263,6 @@ class JingleSessionTest : public testing::Test {
     host_socket_.reset(host_socket);
   }
 
-  static void DoNothing() { }
-
   JingleThreadMessageLoop message_loop_;
 
   scoped_ptr<FakeSignalStrategy> host_signal_strategy_;