Original patch by forshaw.

Added a fallback Win32 font information class for win32k lockdown.
This is to support running PDFIUM within the Win32k lockdown by
removing dependancies on USER32/GDI for the font information code.
It falls back to using a freetype/directory enumeration implementation
if it detects the win32k system calls have been disabled by policy.

BUG=523278
R=tsepez@chromium.org

Review URL: https://codereview.chromium.org/1306883002 .