Update libpng from 1.6.22 -> 1.6.34

Updates third_party/libpng16 to Chromium's third_party/libpng @
a0e5c6a798a45a0dca175e2774ae0edc6aafc696 and applies PDFium specific
patches.

Originally landed as https://pdfium-review.googlesource.com/41910, but
reverted.

Bug=chromium:880322

Change-Id: Ib8249cb156135d028c02f67f9559bdd8695c04f5
Reviewed-on: https://pdfium-review.googlesource.com/42030
Reviewed-by: Lei Zhang <thestig@chromium.org>
Commit-Queue: Ryan Harrison <rharrison@chromium.org>

1 files changed, 0 insertions, 47 deletions

diff --git a/third_party/libpng16/0003-check-errors-in-set-pcal.patch b/third_party/libpng16/0003-check-errors-in-set-pcal.patch
deleted file mode 100644
index 58e27ba623..0000000000
--- a/third_party/libpng16/0003-check-errors-in-set-pcal.patch
+++ /dev/null
@@ -1,47 +0,0 @@
-diff --git a/pngset.c b/pngset.c
-index cccd9cd..83d6ce2 100644
---- a/pngset.c
-+++ b/pngset.c
-@@ -283,17 +283,29 @@ png_set_pCAL(png_const_structrp png_ptr, png_inforpinfo_ptr,
- 
-    /* Check that the type matches the specification. */
-    if (type < 0 || type > 3)
--      png_error(png_ptr, "Invalid pCAL equation type");
-+   {
-+      png_chunk_report(png_ptr, "Invalid pCAL equation type",
-+            PNG_CHUNK_WRITE_ERROR);
-+      return;
-+   }
- 
-    if (nparams < 0 || nparams > 255)
--      png_error(png_ptr, "Invalid pCAL parameter count");
-+   {
-+      png_chunk_report(png_ptr, "Invalid pCAL parameter count",
-+            PNG_CHUNK_WRITE_ERROR);
-+      return;
-+   }
- 
-    /* Validate params[nparams] */
-    for (i=0; i<nparams; ++i)
-    {
-       if (params[i] == NULL ||
-           !png_check_fp_string(params[i], strlen(params[i])))
--         png_error(png_ptr, "Invalid format for pCAL parameter");
-+      {
-+         png_chunk_report(png_ptr, "Invalid format for pCAL parameter",
-+               PNG_CHUNK_WRITE_ERROR);
-+         return;
-+      }
-    }
- 
-    info_ptr->pcal_purpose = png_voidcast(png_charp,
-@@ -301,8 +313,8 @@ png_set_pCAL(png_const_structrp png_ptr, png_inforpinfo_ptr,
- 
-    if (info_ptr->pcal_purpose == NULL)
-    {
--      png_warning(png_ptr, "Insufficient memory for pCAL purpose");
--
-+      png_chunk_report(png_ptr, "Insufficient memory for pCAL purpose",
-+            PNG_CHUNK_WRITE_ERROR);
-       return;
-    }