NaCl: Update revision in DEPS, r8575 -> r8592

This pulls in the following Native Client changes:

r8576: (mseaborn) Thread suspension: Add tests that use real untrusted threads
r8577: (khim) Use slower, table-based validator for MSVC 2008, ASAN and Apple-LLVM
r8578: (khim) Add change lost from CL 8577
r8579: (bradchen) Enable hello_world_glibc test for gyp.
r8580: (khim) Roll toolchain deps to rev 8575
r8582: (dschuff) Switch the compiler-rt repo to gerrit
r8583: (mseaborn) x86-64: Remove the unused tls_base field
r8584: (khim) Use different actions for different types of commands
r8585: (dschuff) Roll Chrome rev to 136852
r8587: (khim) Disable __cpuidex for MSVC2008.
r8588: (kschimpf) Fix code so that always_precedes and always_follows are consistent.
r8589: (kschimpf) Clean up code to clarify we are only tracking the condition flags of APSR.
r8590: (dschuff) Update compiler_rt_rev to merge with upstream tip
r8591: (robertm) Cleanup the crtbegin/crtend handling.
r8592: (robertm) Enabling rudimentary pthread testing

BUG=none
TEST=nacl_integration

Review URL: https://chromiumcodereview.appspot.com/10386126

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@137226 0039d316-1c4b-4281-b951-d872f2087c98

DEPS

@@ -8,7 +8,7 @@ vars = {
   "webkit_revision": "117086",
   "chromium_git": "http://git.chromium.org/git",
   "swig_revision": "69281",
-  "nacl_revision": "8575",
+  "nacl_revision": "8592",
   # After changing nacl_revision, run 'glient sync' and check native_client/DEPS
   # to update other nacl_*_revision's.
   "nacl_tools_revision": "8228",  # native_client/DEPS: tools_rev