Merge to XFA: Don't bother passing -1 as the length to the CFX_ByteString ctor.

TBR=tsepez@chromium.org

Review URL: https://codereview.chromium.org/1406363002 .

(cherry picked from commit 316e482630d5f5d9084edd9725f98a0d89a5bbdf)

Review URL: https://codereview.chromium.org/1406303006 .
5 files changed