Fix some clang warnings with -Wmissing-braces in base.

base/third_party/nspr/prtime.cc

 /* Portions are Copyright (C) 2011 Google Inc */
 /* ***** BEGIN LICENSE BLOCK *****
  * Version: MPL 1.1/GPL 2.0/LGPL 2.1
  *
  * The contents of this file are subject to the Mozilla Public License Version
  * 1.1 (the "License"); you may not use this file except in compliance with
  * the License. You may obtain a copy of the License at
  * http://www.mozilla.org/MPL/
  *
  * Software distributed under the License is distributed on an "AS IS" basis,
@@ skipping 89 matching lines @@
  *------------------------------------------------------------------------
  */
 PRTime
 PR_ImplodeTime(const PRExplodedTime *exploded)
 {
     // This is important, we want to make sure multiplications are
     // done with the correct precision.
     static const PRTime kSecondsToMicroseconds = static_cast<PRTime>(1000000);
 #if defined(OS_WIN)
    // Create the system struct representing our exploded time.
-    SYSTEMTIME st = {0};
-    FILETIME ft = {0};
-    ULARGE_INTEGER uli = {0};
+    SYSTEMTIME st = {};
+    FILETIME ft = {};
+    ULARGE_INTEGER uli = {};
 
     st.wYear = exploded->tm_year;
     st.wMonth = static_cast<WORD>(exploded->tm_month + 1);
     st.wDayOfWeek = exploded->tm_wday;
     st.wDay = static_cast<WORD>(exploded->tm_mday);
     st.wHour = static_cast<WORD>(exploded->tm_hour);
     st.wMinute = static_cast<WORD>(exploded->tm_min);
     st.wSecond = static_cast<WORD>(exploded->tm_sec);
     st.wMilliseconds = static_cast<WORD>(exploded->tm_usec/1000);
      // Convert to FILETIME.
@@ skipping 1120 matching lines @@
                               + 60 * localTime.tm_hour
                               + 1440 * (localTime.tm_mday - 2);
         }
 
   result->tm_params.tp_gmt_offset = zone_offset * 60;
   result->tm_params.tp_dst_offset = dst_offset * 60;
 
   *result_imploded = PR_ImplodeTime(result);
   return PR_SUCCESS;
 }