Merge to XFA: Add some community and testing info to README.md.

Merge to XFA: Add some community and testing info to README.md.

This CL adds some more context to the README on the various test suites and
community mailing lists which are available.

R=thestig@chromium.org

Review URL: https://codereview.chromium.org/1412453004 .

(cherry picked from commit 51cf5bc00dfa3033523355e3e74f3a47f7e46682)

This merge had conflicts.

Committed: https://pdfium.googlesource.com/pdfium/+/1e27a0e1c74e9f772c7434b4708dd2035cae6da8

[dsinclair, 2015-10-16 00:59:45]

PTAL.

Hit merge conflicts when pulling into XFA.

[Lei Zhang, 2015-10-16 01:11:17]

On 2015/10/16 00:59:45, dsinclair wrote:
> PTAL.
> 
> Hit merge conflicts when pulling into XFA.

Is the resolution to make the XFA copy the same as the master copy?

[dsinclair, 2015-10-16 01:16:16]

On 2015/10/16 01:11:17, Lei Zhang wrote:
> On 2015/10/16 00:59:45, dsinclair wrote:
> > PTAL.
> > 
> > Hit merge conflicts when pulling into XFA.
> 
> Is the resolution to make the XFA copy the same as the master copy?

I attempted to merge them together.  The only bit that I didn't originally write
was the part about .png support.

[Lei Zhang, 2015-10-16 01:18:46]

On 2015/10/16 01:16:16, dsinclair wrote:
> On 2015/10/16 01:11:17, Lei Zhang wrote:
> > On 2015/10/16 00:59:45, dsinclair wrote:
> > > PTAL.
> > > 
> > > Hit merge conflicts when pulling into XFA.
> > 
> > Is the resolution to make the XFA copy the same as the master copy?
> 
> I attempted to merge them together.  The only bit that I didn't originally
write
> was the part about .png support.

So are the two copies exactly the same after this CL, or do they still differ
somewhere?

I think both branches have PNG support. If master did not have PNG support, then
there's no way for any of the pixel-based tests to work, since all the
expectation files are PNGs.

[dsinclair, 2015-10-16 01:39:51]

On 2015/10/16 01:18:46, Lei Zhang wrote:
> On 2015/10/16 01:16:16, dsinclair wrote:
> > On 2015/10/16 01:11:17, Lei Zhang wrote:
> > > On 2015/10/16 00:59:45, dsinclair wrote:
> > > > PTAL.
> > > > 
> > > > Hit merge conflicts when pulling into XFA.
> > > 
> > > Is the resolution to make the XFA copy the same as the master copy?
> > 
> > I attempted to merge them together.  The only bit that I didn't originally
> write
> > was the part about .png support.
> 
> So are the two copies exactly the same after this CL, or do they still differ
> somewhere?
> 
> I think both branches have PNG support. If master did not have PNG support,
then
> there's no way for any of the pixel-based tests to work, since all the
> expectation files are PNGs.


Ok, uploaded a new version which makes docs/build.md the exact same as
README.md.

[Lei Zhang, 2015-10-16 02:23:59]

lgtm

[dsinclair, 2015-10-16 15:59:28]

Committed patchset #2 (id:20001) manually as
1e27a0e1c74e9f772c7434b4708dd2035cae6da8 (presubmit successful).