[gdal-dev] Handling pdfium build / integration

[Brad Hards]

I note the recent addition of pdfium for PDF support (alongside podofo and 
poppler).

I'm a bit lost on which pdfium repo and branch to use, the best way to build 
and install pdfium library and headers, and (because of that), how to point the 
GDAL ./configure options to that install.

I'm mainly interested in linux at this stage. Windows differences might be 
interesting later.

I originally did a build of the "upstream" pdfium (after checkout of the repo, 
and then the depot-tools, etc). It took a while, but appeared to succeed.

I assume that the "upstream" pdfium repo is *not* what I want, and that I'm 
meant to use either the "klokantech" or "rouault" repos that do not have V8 
javascript support:

https://github.com/rouault/pdfium
https://github.com/klokantech/pdfium

Based on a manual grab of the build-lin.sh script (I forget which one I used - 
probably klokantech, but they looked very similar), I got what looked like a 
successful build. 

However at this point I'm stuck. Which parts need to get installed for a 
system-wide GDAL install, and what is the recommended way to do that?

After that, I'm hopeful that the ./configure options will be obvious. However 
if there is anything subtle, please feel free to point that out!

Brad