Disable unpack row length when uploading mips

Disable unpack row length when uploading mips

When uploading multiple mip levels, the current path which uses
GL_UNPACK_ROW_LENGTH doesn't work (it fails to reset this value,
and is set incorrectly for subsequent mip levels). This leads
to crashes as the buffer Skia provides to GL is not sized correctly.
This change temporarily disables the GL_UNPACK_ROW_LENGTH path when we
are uploading mips. This path was an optimization, so everything should
continue working as expected.

This is a temporary workaround until we can re-structure the code to
set GL_UNPACK_ROW_LENGTH per mip level.

BUG=609612
GOLD_TRYBOT_URL= https://gold.skia.org/search2?unt=true&query=source_type%3Dgm&master=false&issue=1965973002

Review-Url: https://codereview.chromium.org/1965973002