Merge to XFA: FX_CMapDwordToDword considered harmful.

(cherry picked from commit 85d5c4af4a9546970b34dd413c473d10fef8534b)
Original Review URL: https://codereview.chromium.org/1289703003 .

TBR=thestig@chromium.org

Conflicts:
   core/include/fxcrt/fx_basic.h

BUG=

Review URL: https://codereview.chromium.org/1302783003 .
7 files changed