1.PDfium would be built into the xul (bug 1368948) so PDFiumEngineShim could
call functions directly. However, I still keep loading dynamic library for
debugging purpose. Create a new preference for storing the library file path.
2.Remove redundant define and typedef which are written in PDFium head file.
3.Include an appropriate head file from PDFium.
4.Remove non-used PDFium APIs.
5.Use the singleton pattern to retrieve the instance of PDFiumEngineShim.
6.Don't destroy the library inside PDFiumEngineShim::CloseDocument because the
library has to deal with multi-document.
MozReview-Commit-ID: 97ZBFp1qU8V
This change changes PDFViaEMFPrintHelper so that instead of loading the entire
contents of a PDF document into memory to pass to PDFium, it now simply passes
PDFium a file system path to load the PDF from. This should help us reduce
memory use (and potentially avoid running out of memory) when larger PDFs are
printed.
MozReview-Commit-ID: GISolZYC2GJ
