NaCl: Update revision in DEPS, cc3597c -> 2d8b0bb

This pulls in the following Native Client changes:

a019a57: (dschuff@chromium.org) Update revision for PNaCl
bac8dffa: (stichnot@chromium.org) Add pnacl-translate --sz flag to enable Subzero.
81b0050: (mtrofin@chromium.org) Enable using the toolchain (llvm) provided FileCheck.
3ce68ce: (sbc@chromium.org) Cleanup .gitignore file
7a7bed5: (shinyak@chromium.org) FixPath in CheckObjectSize.
26f4998: (sbc@chromium.org) Remove legacy prep_nacl_sdk.py script
2aa5524: (mtrofin@chromium.org) Updated component revisions.
2d8b0bb: (dschuff@chromium.org) Add lint check for IRT sandbox base address hiding.

Changes: https://chromium.googlesource.com/native_client/src/native_client/+log/cc3597c9c13978079ef85a31d78dc4bf7f18000c..2d8b0bb6ffaf871fdc1f902d38778b2df8c6ff0d

BUG=none
TEST=browser_tests and nacl_integration
CQ_EXTRA_TRYBOTS=tryserver.chromium.linux:linux_chromium_dbg_32_ng,linux_nacl_sdk_build

Review URL: https://codereview.chromium.org/1030213002

Cr-Commit-Position: refs/heads/master@{#322213}

DEPS

@@ -94,7 +94,7 @@ 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': 'cc3597c9c13978079ef85a31d78dc4bf7f18000c',
+  'nacl_revision': '2d8b0bb6ffaf871fdc1f902d38778b2df8c6ff0d',
 }
 
 # Only these hosts are allowed for dependencies in this DEPS file.