Coverity: Initialize member variables.

ppapi/native_client/src/shared/ppapi_proxy/browser_ppp.h

 // Copyright (c) 2011 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.
 
 #ifndef NATIVE_CLIENT_SRC_SHARED_PPAPI_PROXY_BROWSER_PPP_H_
 #define NATIVE_CLIENT_SRC_SHARED_PPAPI_PROXY_BROWSER_PPP_H_
 
 #include <stdarg.h>
 
 #include "native_client/src/include/nacl_macros.h"
@@ skipping 19 matching lines @@
  public:
   BrowserPpp(NaClSrpcChannel* main_channel, plugin::Plugin* plugin)
       : main_channel_(main_channel),
         is_nexe_alive_(true),
         plugin_pid_(0),
         plugin_(plugin),
         ppp_instance_interface_(NULL),
         ppp_messaging_interface_(NULL),
         ppp_input_event_interface_(NULL) {
     CHECK(main_channel_ != NULL);
+    upcall_thread_.tid = 0;
   }
 
   ~BrowserPpp() {}
 
   int32_t InitializeModule(PP_Module module_id,
                            PPB_GetInterface get_browser_interface);
 
   // Joins upcall thread, drops references to channel (owned by plugin),
   // calls plugin side shutdown, but not user's PPP_ShutdownModule.
   void ShutdownModule();
@@ skipping 43 matching lines @@
   const PPP_InputEvent* ppp_input_event_interface_;
 
   // The thread used to handle calls on other than the main thread.
   struct NaClThread upcall_thread_;
   NACL_DISALLOW_COPY_AND_ASSIGN(BrowserPpp);
 };
 
 }  // namespace ppapi_proxy
 
 #endif  // NATIVE_CLIENT_SRC_SHARED_PPAPI_PROXY_BROWSER_PPP_H_