Fix blank page issue caused by too strict correction on bpc

For bit per component (bpc), PDF spec mentions that a RunLengthDecode or DCTDecode filter shall always deliver 8-bit samples. However, some PDF files don't follow this rule. We can find that filter is RunLengthDecode but bpc is 1 in the provided test file. In this case, pdfium will correct bpc to 8 but the actual bpc is 1. It causes a failure because the data is much more than the expected. To handle this case, pdfium doesn't correct bpc to 8 when the original bpc is 1.

BUG=512557
R=tsepez@chromium.org

Review URL: https://codereview.chromium.org/1328213002 .
3 files changed