Update libpng to 1.6.22

third_party/libpng/LICENSE

Index: third_party/libpng/LICENSE
diff --git a/third_party/libpng/LICENSE b/third_party/libpng/LICENSE
index 61d20bd924ae58e137dba0148b86ab1f4903dd54..30dc12433ccbf4110182842ffa26294924ba2edf 100644
--- a/third_party/libpng/LICENSE
+++ b/third_party/libpng/LICENSE
@@ -8,20 +8,22 @@ COPYRIGHT NOTICE, DISCLAIMER, and LICENSE:
 If you modify libpng you may insert additional notices immediately following
 this sentence.
 
-pngusr.h is distributed under the MPL 1.1/GPL 2.0/LGPL 2.1 tri-license.
+Using custom versions of pnglibconf.h and pngprefix.h for Chrome.
 
 This code is released under the libpng license.
 
-libpng versions 1.0.7, July 1, 2000, through 1.2.56, December 17, 2015, are
-Copyright (c) 2000-2002, 2004, 2006-2015 Glenn Randers-Pehrson, are
+libpng versions 1.0.7, July 1, 2000 through 1.6.22, May 26, 2016 are
+Copyright (c) 2000-2002, 2004, 2006-2016 Glenn Randers-Pehrson, are
 derived from libpng-1.0.6, and are distributed according to the same
 disclaimer and license as libpng-1.0.6 with the following individuals
 added to the list of Contributing Authors:
 
    Simon-Pierre Cadieux
    Eric S. Raymond
+   Mans Rullgard
    Cosmin Truta
    Gilles Vollant
+   James Yu
 
 and with the following additions to the disclaimer:
 
@@ -32,6 +34,10 @@ and with the following additions to the disclaimer:
    risk of satisfactory quality, performance, accuracy, and effort is with
    the user.
 
+Some files in the "contrib" directory and some configure-generated
+files that are distributed with libpng have other copyright owners and
+are released under other open source licenses.
+
 libpng versions 0.97, January 1998, through 1.0.6, March 20, 2000, are
 Copyright (c) 1998-2000 Glenn Randers-Pehrson, are derived from
 libpng-0.96, and are distributed according to the same disclaimer and
@@ -55,6 +61,9 @@ Contributing Authors:
    Greg Roelofs
    Tom Tanner
 
+Some files in the "scripts" directory have other copyright owners
+but are released under this license.
+
 libpng versions 0.5, May 1995, through 0.88, January 1996, are
 Copyright (c) 1995-1996 Guy Eric Schalnat, Group 42, Inc.
 
@@ -95,18 +104,29 @@ appreciated.
 
 END OF COPYRIGHT NOTICE, DISCLAIMER, and LICENSE.
 
-A "png_get_copyright" function is available, for convenient use in "about"
-boxes and the like:
+TRADEMARK:
 
-   printf("%s", png_get_copyright(NULL));
+The name "libpng" has not been registered by the Copyright owner
+as a trademark in any jurisdiction.  However, because libpng has
+been distributed and maintained world-wide, continually since 1995,
+the Copyright owner claims "common-law trademark protection" in any
+jurisdiction where common-law trademark is recognized.
 
-Also, the PNG logo (in PNG format, of course) is supplied in the
-files "pngbar.png" and "pngbar.jpg (88x31) and "pngnow.png" (98x31).
+OSI CERTIFICATION:
 
 Libpng is OSI Certified Open Source Software.  OSI Certified Open Source is
 a certification mark of the Open Source Initiative. OSI has not addressed
 the additional disclaimers inserted at version 1.0.7.
 
+EXPORT CONTROL:
+
+The Copyright owner believes that the Export Control Classification
+Number (ECCN) for libpng is EAR99, which means not subject to export
+controls or International Traffic in Arms Regulations (ITAR) because
+it is open source, publicly available software, that does not contain
+any encryption software.  See the EAR, paragraphs 734.3(b)(3) and
+734.7(b).
+
 Glenn Randers-Pehrson
 glennrp at users.sourceforge.net
-December 17, 2015
+May 26, 2016