Switch Chrome on Linux to libc++

Design doc detailing the changes at [1], and announcement to
chromium-dev at [2].

In addition, this CL updates perf_expectations to increase the number
of allowed static initializers.  libc++ adds some initializers from
iostream.cpp.  However, this case is net-neutral since the initializer
used to live in libstdc++, but has been pushed into the chrome and
nacl executables.  The perf_expectations change also required adding
NOPRESUBMIT=true to silence a bogus warning.

[1] https://docs.google.com/document/d/1zmHUXlpGNXB433wHnr40dLwj7c-USsIVlyAeH7vOI9o/edit#heading=h.bfky2xssferh
[2] https://groups.google.com/a/chromium.org/forum/?fromgroups#!topic/chromium-dev/z2YnFCxq0MA

BUG=593874
R=thakis@chromium.org
TBR=rdevlin.cronin@chromium.org
CC=thestig@chromium.org
NOPRESUBMIT=true
CQ_INCLUDE_TRYBOTS=master.tryserver.chromium.linux:linux_chromium_dbg_ng;master.tryserver.chromium.linux:linux_arm;master.tryserver.chromium.linux:linux_chromium_archive_rel_ng;master.tryserver.chromium.linux:linux_chromium_dbg_32_ng

Review-Url: https://codereview.chromium.org/2933573002
Cr-Commit-Position: refs/heads/master@{#483498}
8 files changed