YACReader for Windows uses a shared library version of pdfium.

pdfium branch used for building: chromium/3729

Build parameters used (gn args):

pdf_enable_v8 = false
pdf_enable_xfa = false
is_debug = false
symbol_level = 0
use_jumbo_build = true

For 32 bit builds:
target_cpu="x86"

For 64 bit builds:
target_cpu="x64"

Instructions on building pdfium can be found at https://pdfium.googlesource.com/pdfium

To build a shared library, the source code has to be patched. A patch file with the
necessary modifications can be found in this directory (pdfium_shared_library.patch).

It is recommended to always use the branch the current stable version of Chromium uses.
To get the pdfium branch corresponding to Chromium stable, look at 
http://omahaproxy.appspot.com and search for the true_branch variable associated with
the current stable dev channel of Chromium.