Optimize CPDF_CMapParser

In this parser, a vector of CodeRange values are built up during
operations that need to be sync'd with the CPDF_CMap that is being
initialized. In the existing implementation, the vector being built as
a member var for the parser, and copying the values over to the cmap
whenever there is a change. When profiling, this copy is where the code
spends most of its time.

The code has been rewritten to have the parser reference/modify the
instance of the vector in the cmap instead of having its own copy. This
removes all of the copies and significantly speeds things up.

BUG=chromium:881678

Change-Id: Ib8e75962507ca3d3b1ed066fd1faa4fbb7141122
Reviewed-on: https://pdfium-review.googlesource.com/42350
Commit-Queue: Ryan Harrison <rharrison@chromium.org>
Reviewed-by: Henrique Nakashima <hnakashima@chromium.org>

0 files changed, 0 insertions, 0 deletions