Update tools from Chromium.

Change-Id: I3bf5fcb210c181c3f7131304e41027ba081e3c0e
Reviewed-on: https://boringssl-review.googlesource.com/16145
Reviewed-by: Steven Valdez <svaldez@google.com>
diff --git a/util/bot/update_clang.py b/util/bot/update_clang.py
index 7e91113..d23abfc 100644
--- a/util/bot/update_clang.py
+++ b/util/bot/update_clang.py
@@ -22,7 +22,7 @@
 # CLANG_REVISION and CLANG_SUB_REVISION determine the build of clang
 # to use. These should be synced with tools/clang/scripts/update.py in
 # Chromium.
-CLANG_REVISION = "296320"
+CLANG_REVISION = "300839"
 CLANG_SUB_REVISION = "1"
 
 PACKAGE_VERSION = "%s-%s" % (CLANG_REVISION, CLANG_SUB_REVISION)