roll clang 154450:155352

Also includes new warnings in our style plugin, but those are
currently behind a flag and hence not active.

BUG=none
TEST=none


Review URL: http://codereview.chromium.org/10155019

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@133687 0039d316-1c4b-4281-b951-d872f2087c98

tools/clang/scripts/update.sh

@@ -8,7 +8,7 @@
 # Do NOT CHANGE this if you don't know what you're doing -- see
 # https://code.google.com/p/chromium/wiki/UpdatingClang
 # Reverting problematic clang rolls is safe, though.
-CLANG_REVISION=154450
+CLANG_REVISION=155352
 
 THIS_DIR="$(dirname "${0}")"
 LLVM_DIR="${THIS_DIR}/../../../third_party/llvm"