diff --git a/.clang-format b/.clang-format
index 0f21d0bb9e4a31..6fdf1dc888cb67 100644
--- a/.clang-format
+++ b/.clang-format
@@ -1,4 +1,8 @@
 # Defines the Chromium style for automatic reformatting.
 # http://clang.llvm.org/docs/ClangFormatStyleOptions.html
 BasedOnStyle: Chromium
+# This defaults to 'Auto'. Explicitly set it for a while, so that
+# 'vector<vector<int> >' in existing files gets formatted to
+# 'vector<vector<int>>'. ('Auto' means that clang-format will only use
+# 'int>>' if the file already contains at least one such instance.)
 Standard: Cpp11
diff --git a/DEPS b/DEPS
index 610b1006383d15..3632f51824a11f 100644
--- a/DEPS
+++ b/DEPS
@@ -64,7 +64,7 @@ vars = {
   # Three lines of non-changing comments so that
   # the commit queue can handle CLs rolling build tools
   # and whatever else without interference from each other.
-  'buildtools_revision': '56bc51aff4175d3fa27dcd0faa2c345ab046c8a5',
+  'buildtools_revision': '51ca1f25a2ecea34069cb3ff35394dc53b6fd657',
   # Three lines of non-changing comments so that
   # the commit queue can handle CLs rolling PDFium
   # and whatever else without interference from each other.