NaCl: Update revision in DEPS, 26c7e6a -> c4c237c
NaCl: Update revision in DEPS, 26c7e6a -> c4c237c

This pulls in the following Native Client changes:

95163bf: (stichnot@chromium.org) Update revision for PNaCl
abee7c9: (petarj@mips.com) PNaCl: Update llvm revision in pnacl/COMPONENT_REVISIONS
b44e8dc: (petarj@mips.com) [MIPS] Make $t8 point to the address of TLS pointers
11ff949: (thakis@chromium.org) clang/win: Fix -Wsign-compare warning in platform_impl.cc
f39aa44: (mseaborn@chromium.org) PNaCl: Update llvm revision in pnacl/COMPONENT_REVISIONS: add ConvertToPSO
aebc3c4: (mcgrathr@chromium.org) Update chrome_rev
c4c237c: (erikchen@chromium.org) Back dynamic text regions with a Mach memory region.

Changes: https://chromium.googlesource.com/native_client/src/native_client/+log/26c7e6ae1327a43c948f4666fef9e84fe351ab7c..c4c237c0567cbe1c7de664a4d81673c3403cf55b

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/1580293003

Cr-Commit-Position: 972c6d2dc6dd5efdad1377c0d224e03eb8f276f7@{#369294}

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