Check in the libxml roll script.

third_party/libxml/README.chromium

Index: third_party/libxml/README.chromium
diff --git a/third_party/libxml/README.chromium b/third_party/libxml/README.chromium
index 392a11a472c53920051aa7ab120c42c50098013b..8d1ad88583b7087a99aac49052d1ba7a4d9396a8 100644
--- a/third_party/libxml/README.chromium
+++ b/third_party/libxml/README.chromium
@@ -12,30 +12,11 @@ libxml2 from libxml.org.
 Modifications:
 - Add helper classes in chromium/libxml_utils.cc and
   chromium/include/libxml/libxml_utils.h.
-- Add second workaround for VS 2015 Update 2 code-gen bug - crbug.com/599427
-- Apply patch contributed here: https://crbug.com/628581#c18
-- Apply patch contributed here: https://crbug.com/620679#c34
-- Apply patch contributed here: https://crbug.com/683629#c9
-- Modify win32/include/libxml/xmlversion.h, mac/include/libxml/xmlversion.h and
-  linux/include/libxml/xmlversion.h to not define these:
-  LIBXML_AUTOMATA_ENABLED
-  LIBXML_C14N_ENABLED
-  LIBXML_CATALOG_ENABLED
-  LIBXML_DEBUG_ENABLED
-  LIBXML_DOCB_ENABLED
-  LIBXML_EXPR_ENABLED
-  LIBXML_LEGACY_ENABLED
-  LIBXML_MODULES_ENABLED
-  LIBXML_REGEXP_ENABLED
-  LIBXML_SCHEMAS_ENABLED
-  LIBXML_SCHEMATRON_ENABLED
-  LIBXML_VALID_ENABLED
-  LIBXML_XINCLUDE_ENABLED
-  LIBXML_XPTR_ENABLED
-  LIBXML_ZLIB_ENABLED
+- Applied these patches in chromium/*.patch:
+  chromium-issue-599427.patch: workaround for VS 2015 Update 2 code-gen bug
+  chromium-issue-620679.patch: See https://crbug.com/620679#c34
+  chromium-issue-628581.patch: See https://crbug.com/628581#c18
+  chromium-issue-683629.patch: See https://crbug.com/683629#c9
+- Delete various unused files, see chromium/roll.py
 
-This import was generated by this script:
-https://github.com/dominiccooney/blink-tools/blob/ac9f8e093ec3d00267d67927a37956e5e8993961/roll.py
-
-To import a new snapshot:
-https://docs.google.com/document/d/18gD61GGEUjFiGqFot4WeV97eyyCa17dTg6r6r7r6ZFE/edit
+This import was generated by the chromium/roll.py script.