chromium-browser: Out of bounds access in PDFium

The CJBig2SymbolDict class in fxcodec/jbig2/JBig2SymbolDict.cpp in PDFium, as used in Google Chrome before 47.0.2526.73, allows remote attackers to cause a denial of service out-of-bounds memory access or possibly have unspecified other impact via a PDF document containing crafted data with JBIG2...