Update freetype to 2.5.4.

Put freetype into third_party directory, cleaning up header files.

Previously freetype header files are in core/src/fxge/freetype and core/include/thirdparties. There were also multiple fx_freetype.h.

This patch removes the additional Foxit wrapper to make further update easier.

Notice, for original freetype source code, the following files are modified and need to be updated accordingly in future update:

third_party/freetype/include/config/ftmodule.h
third_party/freetype/include/config/ftoption.h

BUG=407341
R=thestig@chromium.org

Review URL: https://codereview.chromium.org/815103002
718 files changed