Roll src/native_client/ 9b1c91384..1020e8acc (2 commits).

https://chromium.googlesource.com/native_client/src/native_client.git/+log/9b1c91384020..1020e8acc2e1

$ git log 9b1c91384..1020e8acc --date=short --no-merges --format='%ad %ae %s'
2016-02-25 mseaborn Cleanup: Remove the unused "buildbot=X" Scons option for enabling Valgrind
2016-02-25 mseaborn Scons cleanup: Stop DualLibrary() from compiling source files twice on Linux

CQ_INCLUDE_TRYBOTS=tryserver.chromium.linux:linux_chromium_dbg_32_ng,linux_nacl_sdk_build
TBR=mseaborn@chromium.org

Review URL: https://codereview.chromium.org/1729123004

Cr-Commit-Position: refs/heads/master@{#377654}
diff --git a/DEPS b/DEPS
index c7488d7..8bdc6d1 100644
--- a/DEPS
+++ b/DEPS
@@ -87,7 +87,7 @@
   # 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': '9b1c913840204c4794106c2a6db0068e5be5377a',
+  'nacl_revision': '1020e8acc2e1e511478f389a302916ebabeb5242',
   # Three lines of non-changing comments so that
   # the commit queue can handle CLs rolling dEQP
   # and whatever else without interference from each other.