Update PDFium to 1b24b69.

DEPS

 # This file is used to manage the dependencies of the Chromium src repo. It is
 # used by gclient to determine what version of each dependency to check out, and
 # where.
 #
 # For more information, please refer to the official documentation:
 #   https://sites.google.com/a/chromium.org/dev/developers/how-tos/get-the-code
 #
 # When adding a new dependency, please update the top-level .gitignore file
 # to list the dependency's destination directory.
 #
@@ skipping 48 matching lines @@
   'swarming_revision': 'c28b74ff7a2678b611f4a7ecb3be4f99f15a76fd',
   # Three lines of non-changing comments so that
   # the commit queue can handle CLs rolling ANGLE
   # and whatever else without interference from each other.
   "angle_revision": "ed13636ab93755d324d9366b2c41d343ecc5829c",
   # Three lines of non-changing comments so that
   # the commit queue can handle CLs rolling build tools
   # and whatever else without interference from each other.
   'buildtools_revision': '56bc51aff4175d3fa27dcd0faa2c345ab046c8a5',
   # Three lines of non-changing comments so that
-  # the commit queue can handle CLs rolling PDFIum
+  # the commit queue can handle CLs rolling PDFium
   # and whatever else without interference from each other.
-  'pdfium_revision': '7a649fe262d77f93ad3213f53e973a7665d95a23',
+  'pdfium_revision': '1b24b697659b9b933f336238665c835497464a0b',
   # Three lines of non-changing comments so that
   # the commit queue can handle CLs rolling openmax_dl
   # and whatever else without interference from each other.
   'openmax_dl_revision': '01642706d2b37cb7b9db84add870ea0fdabdf5ad',
   # Three lines of non-changing comments so that
   # the commit queue can handle CLs rolling BoringSSL
   # and whatever else without interference from each other.
   'boringssl_revision': '7ea848165b89577c6e9a1ef12a2cdff9d1beb71f',
   # Three lines of non-changing comments so that
   # the commit queue can handle CLs rolling nss
@@ skipping 717 matching lines @@
     # corresponding .py files have already been deleted.
     'name': 'remove_stale_pyc_files',
     'pattern': 'src/tools/.*\\.py',
     'action': [
         'python',
         'src/tools/remove_stale_pyc_files.py',
         'src/tools',
     ],
   },
 ]