Remove const for plain data types in voice_engine/

BUG=1644
R=henrikg@webrtc.org

Review URL: https://webrtc-codereview.appspot.com/1463004

git-svn-id: http://webrtc.googlecode.com/svn/trunk/webrtc@4018 4adac7df-926f-26a2-2b94-8c16560cd09d
diff --git a/voice_engine/shared_data.h b/voice_engine/shared_data.h
index 99cff04..b20225f 100644
--- a/voice_engine/shared_data.h
+++ b/voice_engine/shared_data.h
@@ -58,9 +58,9 @@
     uint16_t NumOfSendingChannels();
 
     // Convenience methods for calling statistics().SetLastError().
-    void SetLastError(const int32_t error) const;
-    void SetLastError(const int32_t error, const TraceLevel level) const;
-    void SetLastError(const int32_t error, const TraceLevel level,
+    void SetLastError(int32_t error) const;
+    void SetLastError(int32_t error, TraceLevel level) const;
+    void SetLastError(int32_t error, TraceLevel level,
                       const char* msg) const;
 
 protected: