profiler: cleanup unused alternate_timer code

crrev.com/1632253002 removed the only client of alternate_timer.h
This CL removes the unreachable paths in the profiler code which
were there just to support alternate_timer (concretelly TCMALLOC).

BUG=564618

Review URL: https://codereview.chromium.org/1640223002

Cr-Original-Commit-Position: refs/heads/master@{#373286}
Cr-Mirrored-From: https://chromium.googlesource.com/chromium/src
Cr-Mirrored-Commit: bc5681f5a8d1db9c8a9d654531e1008b6065dbdd
1 file changed
tree: 89b821cd351ca2f2f1fd4d598778f178e96f20b8
  1. tools/