Clean data races from system_wrappers_unittests.

 - Remove unittest_utilities that are not used.
 - Remove SetLevelFilter that does not seems necessary and anyhow was racy.

BUG=3549
R=henrike@webrtc.org, henrike

Review URL: https://webrtc-codereview.appspot.com/16819004

git-svn-id: http://webrtc.googlecode.com/svn/trunk@6617 4adac7df-926f-26a2-2b94-8c16560cd09d
diff --git a/webrtc/system_wrappers/source/condition_variable_unittest.cc b/webrtc/system_wrappers/source/condition_variable_unittest.cc
index 0d287b7..b5c1c36 100644
--- a/webrtc/system_wrappers/source/condition_variable_unittest.cc
+++ b/webrtc/system_wrappers/source/condition_variable_unittest.cc
@@ -14,13 +14,11 @@
 #include "webrtc/system_wrappers/interface/critical_section_wrapper.h"
 #include "webrtc/system_wrappers/interface/thread_wrapper.h"
 #include "webrtc/system_wrappers/interface/trace.h"
-#include "webrtc/system_wrappers/source/unittest_utilities.h"
 
 namespace webrtc {
 
 namespace {
 
-const int kLogTrace = false;  // Set to true to enable debug logging to stdout.
 const int kLongWaitMs = 100 * 1000; // A long time in testing terms
 const int kShortWaitMs = 2 * 1000; // Long enough for process switches to happen
 
@@ -143,9 +141,7 @@
 
 class CondVarTest : public ::testing::Test {
  public:
-  CondVarTest()
-    : trace_(kLogTrace) {
-  }
+  CondVarTest() {}
 
   virtual void SetUp() {
     thread_ = ThreadWrapper::CreateThread(&WaitingRunFunction,
@@ -171,7 +167,6 @@
   Baton baton_;
 
  private:
-  ScopedTracing trace_;
   ThreadWrapper* thread_;
 };