Roll libxml to 2.9.3

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 b1f644ffd553ffd400f19980763abb394b930fa8..c3536ee2348dda6f8af44c5dc2c71cbff4182e17 100644
--- a/third_party/libxml/README.chromium
+++ b/third_party/libxml/README.chromium
@@ -1,6 +1,6 @@
 Name: libxml
 URL: http://xmlsoft.org
-Version: 2.9.2
+Version: 2.9.3
 License: MIT
 License File: src/Copyright
 Security Critical: yes
@@ -10,31 +10,21 @@ Description:
 libxml2 from libxml.org.
 
 Modifications:
+- Import https://git.gnome.org/browse/libxml2/commit/?id=a7a94612aa3b16779e2c74e1fa353b5d9786c602 from upstream
 - 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.
-- Self-assignment removed https://bugzilla.gnome.org/show_bug.cgi?id=751679.
 - Include fix for runtime blowups on larger xpath expressions, https://bugzilla.gnome.org/show_bug.cgi?id=760325
+- Fix printf format specifiers, https://chromium.googlesource.com/chromium/src/+/d31995076e55f1aac2f935c53b585a90ece27a11
 
 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
+../src/configure --without-iconv --with-icu --without-ftp --without-http \
+    --without-lzma
 cd ..
 Patch config.h to not define HAVE_RAND_R since we use this file on Android
 and it does not have it.
@@ -45,7 +35,18 @@ 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.
+Then copy VC10/config.h and include/libxml/xmlversion.h to win32/ on Linux.
 
+Remove:
+  src/doc/
+  src/example/
+  src/macos/libxml2.mcp.xml.sit.hqx
+  src/os400/
+  src/python/
+  src/result/
+  src/test/
+  src/vms/
+  src/win32/wince
+  src/VxWorks/
 
 Update BUILD.gn and libxml.gyp as necessary to add/remove files, etc.