GitLab

This pulls in the following Native Client changes:

r13581: (dschuff) Further deduplicate and simplify PNaCl SCons testing
r13582: (dschuff) Remove unneeded items from list of trusty cross toolchain packages.
r13583: (dschuff) Add toolchain_build/git_cache to list of SVN ignores
r13584: (sbc) Fix for ARM cross build with clang.
r13586: (dschuff) Update x86-64 linux prep script for Trusty
r13589: (noelallen) NaCl has it's own copy of the build files, including several GNI files which use "declare_args" to provide build options.
r13592: (sheyang) Add PROJECT field to codereview.settings for nacl

BUG=none
TEST=browser_tests and nacl_integration
CQ_EXTRA_TRYBOTS=tryserver.chromium.linux:linux_rel_precise32,linux_nacl_sdk_build

Review URL: https://codereview.chromium.org/449063002

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@288166 0039d316-1c4b-4281-b951-d872f2087c98