Roll pdfium.

This brings in:
f105b19 No need to release resources in destructor of CPDF_ShadingObject
fdcc874 Restrict index not be greater than row_size in TIFF_PredictLine
405478d Use valid bpc value in LoadPalette() and ContinueToLoadMask()
a67da71 Fix a bug when looping through m_pCompData
96f8786 Bounds check before fixed-size memcmp() in CJPX_Decoder::Init().

TBR=thakis@chromium.org

Review URL: https://codereview.chromium.org/515983005

Cr-Commit-Position: refs/heads/master@{#292502}

DEPS

@@ -62,7 +62,7 @@ vars = {
   # Three lines of non-changing comments so that
   # the commit queue can handle CLs rolling PDFIum
   # and whatever else without interference from each other.
-  'pdfium_revision': '02e6ca4c4fc94f72fa7aac326234dfd8a9f61d23',
+  'pdfium_revision': 'f105b19434fdeecac2dd2f78fed5b45ed2637ab3',
   # 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.