XFA: Manual merge of Clean up IFX_BidiChar

XFA: Manual merge of Clean up IFX_BidiChar

- Replace IFX_BidiChar with just CFX_BidiChar
- Document implementation
- Change out parameters to pointers
- Remove dead code
- Add an enum for bidi directions
- Move several externs to a header
- Add unit tests

Original CL: https://codereview.chromium.org/1197643002

This version does not remove fx_arb.h and fx_arabic.h, as there is code
on the XFA branch that still uses parts of it.

R=tsepez@chromium.org

Committed: https://pdfium.googlesource.com/pdfium/+/ee02ea37e8f85920885600d56df706d690e648ff

[Lei Zhang, 2015-10-27 02:36:45]

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

[Lei Zhang, 2015-10-27 02:36:46]

- Some pieces of the original CL has been merged already.
- fx_arb.h / fx_arabic.* will remain unique to XFA for now. We'll have to figure
out:
-- what's dead code.
-- what can be moved over to fx_bidi, or just kept in fx_arabic.

[Tom Sepez, 2015-10-27 16:34:35]

I think you need to add new unittest to .gyp/.gn files.

[Tom Sepez, 2015-10-27 16:41:06]

https://codereview.chromium.org/1423103002/diff/20001/core/include/fxcrt/fx_a...
File core/include/fxcrt/fx_arb.h (right):

https://codereview.chromium.org/1423103002/diff/20001/core/include/fxcrt/fx_a...
core/include/fxcrt/fx_arb.h:14: #ifdef __cplusplus
nit: this file won't compile under C given the classes above.  So you can just
extern "C" it, period.  Having done that, I didn't see a reason why this would
need C calling semantics (e.g. not passed as fn pointers).

https://codereview.chromium.org/1423103002/diff/20001/core/include/fxcrt/fx_a...
core/include/fxcrt/fx_arb.h:38: };
nit: no ; here.

[Tom Sepez, 2015-10-29 17:12:52]

Let me know when you get this to land; I'd like to re-generate the core
master/xfa diffs again.

[Lei Zhang, 2015-10-29 21:51:39]

On 2015/10/27 16:34:35, Tom Sepez wrote:
> I think you need to add new unittest to .gyp/.gn files.

Done.

[Tom Sepez, 2015-10-29 21:56:15]

lgtm

[Lei Zhang, 2015-10-29 21:59:06]

uh, still need to address your comments, PTAL at PS 5.

https://codereview.chromium.org/1423103002/diff/20001/core/include/fxcrt/fx_a...
File core/include/fxcrt/fx_arb.h (right):

https://codereview.chromium.org/1423103002/diff/20001/core/include/fxcrt/fx_a...
core/include/fxcrt/fx_arb.h:14: #ifdef __cplusplus
On 2015/10/27 16:41:05, Tom Sepez wrote:
> nit: this file won't compile under C given the classes above.  So you can just
> extern "C" it, period.  Having done that, I didn't see a reason why this would
> need C calling semantics (e.g. not passed as fn pointers).

Done.

https://codereview.chromium.org/1423103002/diff/20001/core/include/fxcrt/fx_a...
core/include/fxcrt/fx_arb.h:38: };
On 2015/10/27 16:41:05, Tom Sepez wrote:
> nit: no ; here.

Done.

[Tom Sepez, 2015-10-29 22:00:55]

still lgtm.  The others were kinda optional.

[Lei Zhang, 2015-10-29 22:02:01]

Committed patchset #5 (id:80001) manually as
ee02ea37e8f85920885600d56df706d690e648ff (presubmit successful).