Use a temp file in FileLockTest.
Use a temp file in FileLockTest.

Permits running FileLockTests in parallel as the lock files don't
conflict with concurrent runs.

BUG=4137
R=pthatcher@webrtc.org

Review URL: https://webrtc-codereview.appspot.com/37519004

git-svn-id: 917f5d3ca488f358c4d40eaec14422cf392ccec9@7996 4adac7df-926f-26a2-2b94-8c16560cd09d

TimothyGu/libilbc,TimothyGu/libilbc,ShiftMediaProject/libilbc,TimothyGu/libilbc,ShiftMediaProject/libilbc,TimothyGu/libilbc,ShiftMediaProject/libilbc,TimothyGu/libilbc,ShiftMediaProject/libilbc,ShiftMediaProject/libilbc