Increase MessageAttachmentSet::kMaxDescriptorsPerMessage to 128
so that dynamically linked NaCl applications like ARC (App Runtime
for Chrome) start faster.
ARC is a dynamically linked NaCl application which lists more than
70 DSO files in its nmf file. crrev.com/319931 allowed Chrome to
pre-open up to 2 DSO files when it spawns a NaCl plugin process so
that the plugin process can open/read/map the DSO files without
issuing any Chrome IPC. This CL increase the number of DSO files
Chrome can pre-open from 2 to 120+.
BUG=348232
BUG=nativeclient:3802
TEST=ipc_tests, browser_tests (*PackagedAppTest.SuccessfulLoad)
TEST=manually tested non-SFI ARC apps
Review URL: https://codereview.chromium.org/
998833002
Cr-Commit-Position: refs/heads/master@{#320831}