Remove serving_dirs usage in speedometer2

The serving dir is also included by the page.

Bug: chromium:883798
Change-Id: I1d1a512774b69312642b6226a80023ac88ff3293
Reviewed-on: https://chromium-review.googlesource.com/1226752
Reviewed-by: Ned Nguyen <nednguyen@google.com>
Commit-Queue: Vovo Yang <vovoy@chromium.org>
Cr-Commit-Position: refs/heads/master@{#591301}
1 file changed