NaCl: Update revision in DEPS, r12730 -> r12757

This pulls in the following Native Client changes:

r12731: (jvoung) Turn on tests/callingconv_case_by_case for PNaCl --target=i686-nacl.
r12732: (bradnelson) Dropping remaining python_26 references.
r12734: (mcgrathr) Default to all trybot sets when pynacl/ code is touched
r12735: (kschimpf) Add pnacl-compress driver tool to compress pnacl bitcode files.
r12736: (halyavin) Fix more instances of use-after-free due to incorrect clean up.
r12737: (sbc) Update newlib revision used by toolchain builders.
r12738: (dyen) build_nexe.py can now apply tls_edit
r12739: (dyen) tls_edit only prints out verbose messages in scons
r12740: (mseaborn) Remove irt_ppapi.{c,h}, which have been moved to the Chromium repo
r12741: (jfb) Toolchain build: add sync-only option.
r12742: (noelallen) Add a bootstrap target for bionic LIBC to generate only the static libc components....
r12743: (mseaborn) Cleanup: Remove "ppapi" directory from IRT's #include search path
r12744: (noelallen) Roll to get missing files
r12745: (mseaborn) Cleanup: Remove PPAPI directories from include_rules, used by checkdeps
r12746: (dschuff) Run LLVM regression tests for toolchain_build_pnacl build
r12747: (noelallen) Roll Bionic in TOOL_REVISIONS
r12748: (jvoung) Show summary even w/out errors in *.sh bots, to be more like buildbot_lib.py.
r12749: (dschuff) once.py: Don't override fresh build if use-cached-results is disabled
r12750: (sbc) Roll newlib toolchain versions in TOOL_REVISIONS
r12751: (mcgrathr) toolchain_build: Build for x86_64-linux host too
r12752: (dyen) Fixed issue with applying tls_edit in windows
r12753: (dschuff) PNaCl translator: use multithreading for sandboxed translation
r12754: (sbc) Update hashes in TOOL_REVISIONS.
r12755: (jvoung) Revert "Show summary even w/out errors in *.sh bots, to be more like buildbot_lib.py."
r12756: (yyanagisawa) make goma to compile code for pnacl-clang.
r12757: (dschuff) pnacl-nativeld: Use RunWithSplit RPC instead of RunWithDefaultCmdLine

BUG=none
TEST=browser_tests and nacl_integration
R=bradnelson@google.com

Review URL: https://codereview.chromium.org/163993002

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@251343 0039d316-1c4b-4281-b951-d872f2087c98

DEPS

@@ -28,7 +28,7 @@ vars = {
   "chromiumos_git": "https://chromium.googlesource.com/chromiumos",
   "skia_git": "https://skia.googlesource.com",
   "swig_revision": "230490",
-  "nacl_revision": "12730",
+  "nacl_revision": "12757",
   # After changing nacl_revision, run 'glient sync' and check native_client/DEPS
   # to update other nacl_*_revision's.
   "nacl_tools_revision": "12655",  # native_client/DEPS: tools_rev