NEW public API for pdfwindow font manipulation

NEW public API for pdfwindow font manipulation.

PDFium side of fix to make chromium free of private header
includes.  This moves the one snippet of contaminating code
from chrome to PDFium itself.

BUG=486818
R=thestig@chromium.org

Committed: https://pdfium.googlesource.com/pdfium/+/8f6445b83139349fa31a137496d54b1847a66d7c

[Tom Sepez, 2015-05-11 23:18:49]

tsepez@chromium.org changed reviewers:
+ thestig@chromium.org

[Tom Sepez, 2015-05-11 23:40:13]

Lei, for review.

[Lei Zhang, 2015-05-12 00:46:24]

Should we expose CPWL_FontMap::CharsetFontMap as FPDF_CharsetFontMap, and
provide a function to get |CPWL_FontMap::defaultTTFMap| ?

It's not obvious if FPDF_AlternateTTFEnumFontsCallback() is useful to any other
PDFium consumers.

[Tom Sepez, 2015-05-12 15:51:21]

On 2015/05/12 00:46:24, Lei Zhang wrote:
> Should we expose CPWL_FontMap::CharsetFontMap as FPDF_CharsetFontMap, and
> provide a function to get |CPWL_FontMap::defaultTTFMap| ?
> 
> It's not obvious if FPDF_AlternateTTFEnumFontsCallback() is useful to any
other
> PDFium consumers.
Yeah, ok, I was hoping to avoid introducing a data structure, but this does seem
cleaner.

[Tom Sepez, 2015-05-12 17:08:19]

Updated.

[Lei Zhang, 2015-05-12 18:14:46]

lgtm

[Tom Sepez, 2015-05-12 19:24:27]

Committed patchset #2 (id:20001) manually as
8f6445b83139349fa31a137496d54b1847a66d7c (presubmit successful).