Convert from int to float values.
Convert from int to float values.

The CPDF_Page::GetDisplayMatrix expects to set float values into the
|display_matrix| but all of the input values are currently int. It is possible
to overflow the int values, so this CL changes the variables to be int which
closer reflects what they're being used for.

BUG=chromium:652038

Review-Url: https://codereview.chromium.org/2412983002

DrAlexx/pdfium,DrAlexx/pdfium,DrAlexx/pdfium,DrAlexx/pdfium