[formcalc] Cleanup if expression parsing.

This CL simplifies the if expression parsing. The elseif construct has
been split into its own list of IfExpressions and no longer gets
stuffed into the elseExpression. A loop was added into the output methods
for the elseif expressions, which also means we can go from having:

if () {
} else {
  if () {
  } else {
  }
}

to
if () {
} else if () {
} else {
}

Which is a bit nicer.

Change-Id: I6edf75215500d6a32a8d7218d477b6960f03de51
Reviewed-on: https://pdfium-review.googlesource.com/27571
Reviewed-by: Ryan Harrison <rharrison@chromium.org>
Commit-Queue: dsinclair <dsinclair@chromium.org>

0 files changed, 0 insertions, 0 deletions