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If a delayloaded function is patched using IATPatchFunction and then
later there are method calls to the same DLL, the delayloadhelper will
fully realize the IAT for that DLL, overwriting the patch. This change
forces all of the imports to get loaded before the patch is created.

The primary scenario for this is the GDI patch for GetFontData done in
InitializePDF(). This presents a problem, however, because this method
is currently called during startup for every child process, thus
negating the work done to make GDI delayloaded in the first place. As
such, this change also makes two optimizations to prevent losing the
delayload perf benefits:
1. For PDF (ppapi) processes, ensures InitializePDF's patches only run
on Win7 and Win8. This is done because Win10 uses different font
retrieval mechanisms because of win32k process mitigations.
2a. Ensures InitializePDF runs for ppapi processes. Since this
code is only actually needed for PDF rendering, there's no reason to
do it for every child process. The LoadAllImports + patching then
becomes pay-for-play when a PDF is being viewed.
2b. Ensures InitializePDF runs for printing utility processes which use
the GDI-based font information on all Windows versions.

Bug: 988164
Change-Id: I4d3c560a7c022c09251773c2a0d1cb4585da2145
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/1731175
Commit-Queue: Cliff Smolinsky <cliffsmo@microsoft.com>
Reviewed-by: Lei Zhang <thestig@chromium.org>
Reviewed-by: Bruce Dawson <brucedawson@chromium.org>
Reviewed-by: Greg Thompson <grt@chromium.org>
Cr-Commit-Position: refs/heads/master@{#686696}