- Add a SetPriority method to ThreadWrapper

- Remove 'priority' from CreateThread and related member variables from implementations
- Make supplying a name for threads, non-optional

BUG=
R=magjed@webrtc.org

Review URL: https://webrtc-codereview.appspot.com/44729004

Cr-Commit-Position: refs/heads/master@{#8810}
git-svn-id: http://webrtc.googlecode.com/svn/trunk@8810 4adac7df-926f-26a2-2b94-8c16560cd09d

webrtc/system_wrappers/source/data_log.cc

@@ -349,13 +349,11 @@ int DataLogImpl::CreateLog() {
 
 int DataLogImpl::Init() {
   file_writer_thread_ = ThreadWrapper::CreateThread(
-                          DataLogImpl::Run,
-                          instance_,
-                          kHighestPriority,
-                          "DataLog");
+      DataLogImpl::Run, instance_, "DataLog");
   bool success = file_writer_thread_->Start();
   if (!success)
     return -1;
+  file_writer_thread_->SetPriority(kHighestPriority);
   return 0;
 }