Upgrading libpng to 1.2.46 to fix a few vulnerabilities.

Bug: 5057432
Bug: 5055636
Change-Id: I9e1b51881386aa9f574a38abc844e036baef9091
diff --git a/Y2KINFO b/Y2KINFO
index 1cf3a0a..0e2a920 100644
--- a/Y2KINFO
+++ b/Y2KINFO
@@ -1,13 +1,13 @@
    Y2K compliance in libpng:
    =========================
 
-      June 26, 2010
+      July 9, 2011
 
       Since the PNG Development group is an ad-hoc body, we can't make
       an official declaration.
 
       This is your unofficial assurance that libpng from version 0.71 and
-      upward through 1.2.44 are Y2K compliant.  It is my belief that earlier
+      upward through 1.2.46 are Y2K compliant.  It is my belief that earlier
       versions were also Y2K compliant.
 
       Libpng only has three year fields.  One is a 2-byte unsigned integer