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

webrtc/system_wrappers/source/clock.cc

 /*
  *  Copyright (c) 2013 The WebRTC project authors. All Rights Reserved.
  *
  *  Use of this source code is governed by a BSD-style license
  *  that can be found in the LICENSE file in the root of the source
  *  tree. An additional intellectual property rights grant can be found
  *  in the file PATENTS.  All contributing project authors may
  *  be found in the AUTHORS file in the root of the source tree.
  */
 
@@ skipping 137 matching lines @@
     filetime_ref_as_ul.LowPart = ref_point_.file_time.dwLowDateTime;
     filetime_ref_as_ul.QuadPart +=
         static_cast<ULONGLONG>((elapsed_ms.QuadPart) * 1000 * 10);
 
     // Copy to result
     current_time->dwHighDateTime = filetime_ref_as_ul.HighPart;
     current_time->dwLowDateTime = filetime_ref_as_ul.LowPart;
   }
 
   static ReferencePoint GetSystemReferencePoint() {
-    ReferencePoint ref = {0};
-    FILETIME ft0 = {0};
-    FILETIME ft1 = {0};
+    ReferencePoint ref = {};
+    FILETIME ft0 = {};
+    FILETIME ft1 = {};
     // Spin waiting for a change in system time. As soon as this change happens,
     // get the matching call for timeGetTime() as soon as possible. This is
     // assumed to be the most accurate offset that we can get between
     // timeGetTime() and system time.
 
     // Set timer accuracy to 1 ms.
     timeBeginPeriod(1);
     GetSystemTimeAsFileTime(&ft0);
     do {
       GetSystemTimeAsFileTime(&ft1);
@@ skipping 91 matching lines @@
 void SimulatedClock::AdvanceTimeMilliseconds(int64_t milliseconds) {
   AdvanceTimeMicroseconds(1000 * milliseconds);
 }
 
 void SimulatedClock::AdvanceTimeMicroseconds(int64_t microseconds) {
   WriteLockScoped synchronize(*lock_);
   time_us_ += microseconds;
 }
 
 };  // namespace webrtc