Fix a crash in WebRtcRtpDumpHandler.

chrome/browser/media/webrtc_rtp_dump_handler.cc

 // Copyright 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.
 
 #include "chrome/browser/media/webrtc_rtp_dump_handler.h"
 
 #include "base/file_util.h"
 #include "base/logging.h"
 #include "base/strings/string_number_conversions.h"
 #include "base/time/time.h"
@@ skipping 312 matching lines @@
                               base::Bind(base::IgnoreResult(&base::DeleteFile),
                                          outgoing_dump_path_,
                                          false));
 
       DVLOG(2) << "Deleted invalid outgoing dump "
                << outgoing_dump_path_.value();
       outgoing_dump_path_.clear();
     }
   }
 
-  if (!callback.is_null())
-    callback.Run();
-
   // Release the writer when it's no longer needed.
   if (incoming_state_ != STATE_STOPPING && outgoing_state_ != STATE_STOPPING &&
       incoming_state_ != STATE_STARTED && outgoing_state_ != STATE_STARTED) {
     dump_writer_.reset();
     --g_ongoing_rtp_dumps;
   }
+
+  // This object might be deleted after running the callback.
+  if (!callback.is_null())
+    callback.Run();
 }