Upgrade to libxml 2.9.2 and libxslt 1.1.28

third_party/libxml/README.chromium

 Name: libxml
 URL: http://xmlsoft.org
-Version: 2.7.7
+Version: 2.9.2
 License: MIT
 License File: src/Copyright
 Security Critical: yes
 
 Description:
-The src/ directory contains a partial snapshot of the libxml library
-with the patches in the patches/ directories applied.
-See the files in that directory for discussion of their effects.
 
-Current version: 2.7.7.
+libxml2 from libxml.org.
 
 Modifications:
-- Converted to utf-8 with: vim +"argdo write ++enc=utf-8" *.c
-- Import XPath fix http://git.gnome.org/browse/libxml2/commit/?id=91d19754d46acd4a639a8b9e31f50f31c78f8c9c
-- Import follow-on for above commit: http://git.gnome.org/browse/libxml2/commit/?id=ea90b894146030c214a7df6d8375310174f134b9
-- Import additional XPath fix http://git.gnome.org/browse/libxml2/commit/?id=df83c17e5a2646bd923f75e5e507bc80d73c9722
-- Import follow-on fix for above commit: http://git.gnome.org/browse/libxml2/commit/?id=fec31bcd452e77c10579467ca87a785b41115de6
-- And a follow-on fix to the previous two fixes, committed upstream: http://git.gnome.org/browse/libxml2/commit/?id=f5048b3e71fc30ad096970b8df6e7af073bae4cb (slightly differently, but we can drop our local fix on the next roll).
-- Add a fix for handling of unknown namespaces, commit upstream is pending.
-- Add fixes for ending the parse properly if a SAX callback calls xmlStopParser(), commit upstream is pending.
-- Add fix for entities, commit upstream is http://git.gnome.org/browse/libxml2/commit/?id=5bd3c061823a8499b27422aee04ea20aae24f03e
-- Import UTF-8 fix from upstream: http://git.gnome.org/browse/libxml2/commit/?id=0795348aeb86648723bc391e4d02e20631c10bca
-- Import XPath fix http://git.gnome.org/browse/libxml2/commit/xpath.c?id=2ddecc23862bab1a9a9e51e097aefc92ec305e28
-- Merge clang warning fix http://git.gnome.org/browse/libxml2/commit/?id=aae48e64dfbf2b46b157a4c1857e30645116388f
-- Add a fix for proper escaping of xpointer expressions, commit upstream is pending.
-- Add helper classes in chromium/libxml_utils.cc and chromium/include/libxml/libxml_utils.h.
-- Add a tweak to limit problems caused by excessive strings and buffers.
-- Change the xmlNs struct a little bit, so it looks like it has no children
-  if treated as a generic xmlNode object.
-- Fix pretty harmless use-after-free in generate-id function.
-- Merge a clang warning fix http://git.gnome.org/browse/libxml2/commit/?id=713434d2309da469d64b35e163ea6556dadccada
-- Import attribute normalization fix http://git.gnome.org/browse/libxml2/commit/?id=6a36fbe3b3e001a8a840b5c1fdd81cefc9947f0d
-- Merge a redundant comparison fix http://git.gnome.org/browse/libxml2/commit/?id=2af19f985b911b6dc6ada478ba8d201d2ddc9309
-- Merge a redundant comparisons fix https://git.gnome.org/browse/libxml2/commit/?id=eea38159be421dbafbee38f40e239f91734bc713
-- Merge XML_PARSER_EOF checks https://git.gnome.org/browse/libxml2/commit/?id=48b4cdde3483e054af8ea02e0cd7ee467b0e9a50 and https://git.gnome.org/browse/libxml2/commit/?id=e50ba8164eee06461c73cd8abb9b46aa0be81869
-- Prevent snprintf from being defined as _snprintf on VS 2015.
-- Make ucrt of Win10 SDK not define POSIX error codes.
-- Delete/disable nanoftp and nanohttp.
+- Add helper classes in chromium/libxml_utils.cc and
+  chromium/include/libxml/libxml_utils.h.
+- Import https://git.gnome.org/browse/libxml2/commit/?id=7580ce0a7f53891de520fed2c0e360266c286da6
+  from upstream.
 
-To import a new snapshot of libxml:
 
-- Visit http://xmlsoft.org/downloads.html and download the latest source
-  distribution.
-- Copy the files into this directory, omitting files which have been omitted
-  here.  E.g.:  for i in $(find . -type f); do cp ../libxml-newver/$i $i; done
-  This should clobber all local changes to this directory.
-- Apply the patches in patches/ and fix any problems.
-  UPDATE THOSE PATCHES OR EVAN WILL HUNT YOU DOWN.
-- On a Linux system,
-    $ cd linux
-    $ ../configure --without-iconv --without-ftp --without-http
-  to generate config.h and include/libxml/xmlversion.h for Linux.
-- On a Mac,
-    $ cd mac
-    $ ../configure --without-iconv --without-ftp --without-http
-  to generate config.h and include/libxml/xmlversion.h for Macs.
-- On Windows, run build/generate-win32-headers.bat to re-generate config.h and
-  include/libxml/xmlversion.h for Windows builds.
-- Update this README to reflect the new version number.
+To import a new snapshot:
+
+On Linux, get the latest tar, untar, and replace src/ with libxml2-X.Y.Z/.
+
+Remove:
+  src/doc/
+  src/example/
+  src/os400/
+  src/python/
+  src/result/
+  src/test/
+  src/vms/
+  src/VxWorks/
+
+Generate config.h, include/libxml/xmlversion.h, and xml2-config:
+
+cd linux
+../src/configure --without-iconv --with-icu --without-ftp --without-http
+cd ..
+Patch config.h to not define HAVE_RAND_R since we use this file on Android
+and it does not have it.
+
+On a Mac, do the same in the mac/ subdir for config.h and
+include/libxml/xmlversion.h and copy those to the Linux box in mac/
+
+On a Windows box:
+cd libxml2-2.9.2\win32
+cscript //E:jscript configure.js compiler=msvc iconv=no icu=yes ftp=no http=no
+Then copy config.h and include/libxml/xmlversion.h to win32/ on Linux.
+
+
+Update BUILD.gn and libxml.gyp as necessary to add/remove files, etc.
+