Roll ASan/Win to LLVM r228568

This should fix issue 453209 and give better diagnostics for issue 452788

BUG=453209,452788,345874
TBR=rnk@chromium.org
NOTRY=true

Review URL: https://codereview.chromium.org/908763003

Cr-Commit-Position: refs/heads/master@{#315281}

tools/clang/scripts/update.py

@@ -24,7 +24,7 @@ LLVM_WIN_REVISION = 'HEAD'
 # in bringup. Use a pinned revision to make it slightly more stable.
 if (re.search(r'\b(asan)=1', os.environ.get('GYP_DEFINES', '')) and
     not 'LLVM_FORCE_HEAD_REVISION' in os.environ):
-  LLVM_WIN_REVISION = '226810'
+  LLVM_WIN_REVISION = '228568'
 
 # Path constants. (All of these should be absolute paths.)
 THIS_DIR = os.path.abspath(os.path.dirname(__file__))