NaCl: Update revision in DEPS, r13867 -> r13894

This pulls in the following Native Client changes:

r13868: (dschuff) Add setjmp and a simple crtbegin for nacl-clang
r13873: (dschuff) Update revision for PNaCl r13828->r13868
r13874: (dyen) Fixed issue on windows where directory removal sometimes fails.
r13875: (dyen) Added i686-nacl-as and i686-nacl-ld for PNaCl direct to NaCl toolchain.
r13876: (shyamsundarr) stop building/testing old x86 validator.
r13877: (jvoung) Update GCC and GLIBC revisions to revert va_list definition.
r13878: (dschuff) Revert "Pass naclsdk_validate=0 to scons runs run by main waterfall bots"
r13879: (dschuff) Update all newlib revisions to 9f95ad0
r13880: (petarj) PNaCl: Update LLVM revision in pnacl/COMPONENT_REVISIONS
r13881: (dschuff) Update revision for PNaCl r13868->r13879
r13882: (yyanagisawa) Fix: forget to import time.
r13885: (dschuff) Add back one exclusion to libcxx test known failures.
r13886: (jvoung) Update NaCl x86 GCC newlib/glibc revision from 13729 to 13880.
r13887: (mazda) Make nonsfi_tests with pnacl_generate_pexe=0 run on buildbot.
r13888: (dschuff) Add nacl-clang testing to SCons
r13889: (dschuff) Upload packages for nacl_clang libc++ and support libs
r13890: (mcgrathr) Remove floating-point support from serialization library
r13891: (dschuff) Update revision for PNaCl r13879->r13890
r13892: (jvoung) Enable x86-32 cross calling convention test for varargs and va_list and method pointers.
r13894: (dschuff) Run nacl-clang tests on PNaCl bots

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

Review URL: https://codereview.chromium.org/650923002

Cr-Commit-Position: refs/heads/master@{#299325}

DEPS

@@ -96,7 +96,7 @@ vars = {
   # Three lines of non-changing comments so that
   # the commit queue can handle CLs rolling NaCl
   # and whatever else without interference from each other.
-  'nacl_revision': '4d5e6cbfc85ac836d68caab0b7e725ca4d5ddc81', # from svn revision r13867
+  'nacl_revision': '68133f52bee4c8f85269c7c597d781b74a43c700', # from svn revision r13894
 }
 
 # Only these hosts are allowed for dependencies in this DEPS file.