NaCl: Update revision in DEPS, r13251 -> r13261

This pulls in the following Native Client changes:

r13252: (sehr) Make Android scons build align better with gyp android build
r13253: (mseaborn) Add test for PNaCl setjmp() bug in which stack slots get reused wrongly
r13254: (jvoung) Remove -sfi-load, etc. from the pnacl-translate driver (always set for nacl)
r13255: (dyen) Added a way for toolchain_build to update known git mirrors.
r13256: (hamaji) Non-SFI Mode: Build newlib-based Linux static executables for ARM
r13257: (mcgrathr) Include address in ReserveBottomPages failure message
r13258: (sbc) Add {TOOLCHAIN}/usr/local/lib to pnacl library search path.
r13259: (sehr) Fix stlport issues in scons build
r13260: (mcgrathr) Accept mmap EINVAL failure for any <64k page, not just 0
r13261: (jvoung) PNaCl: Update LLVM revision in pnacl/COMPONENT_REVISIONS

BUG=none
TEST=browser_tests and nacl_integration

Review URL: https://codereview.chromium.org/304323011

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@274333 0039d316-1c4b-4281-b951-d872f2087c98

DEPS

@@ -34,7 +34,7 @@ vars = {
   "pdfium_git": "https://pdfium.googlesource.com",
   "skia_git": "https://skia.googlesource.com",
   "swig_revision": "230490",
-  "nacl_revision": "13251",
+  "nacl_revision": "13261",
   # After changing nacl_revision, run 'glient sync' and check native_client/DEPS
   # to update other nacl_*_revision's.
   "nacl_tools_revision": "13077",  # native_client/DEPS: tools_rev