Use std:: versions of math functions.
Use std:: versions of math functions.

The C stdlib versions always assume double types. The C++ std:: versions
are type-correct.

Change-Id: I5619339dbd2454c12ac2f35b8b2ee360b2e1a708
Bug: skia:12034
Reviewed-on: https://skia-review.googlesource.com/c/skia/+/412666
Commit-Queue: John Stiles <f4fcf42d3bb5924557f1eeb3be66747535e585da@google.com>
Auto-Submit: John Stiles <f4fcf42d3bb5924557f1eeb3be66747535e585da@google.com>
Reviewed-by: Brian Osman <794c0b5534edf5601d88e1d41975d0262da12894@google.com>

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