Use int rather than size_t to pass DIP amounts to vector icon functions.

These are basically signed integral values rather than byte lengths in memory.
Clues that back this up:
* The vector icon code cast the values back to int to negate them.
* Nearly all callers actually supplied ints anyway (but by default our compilers
  don't warn on this)
* The rest of views uses ints for px/DIP values

This also makes an SkScalar->integral conversion that was happening implicitly
explicit, using the same conversion the parsing code uses.

BUG=none
TEST=none
TBR=sky

Review-Url: https://codereview.chromium.org/2255403002
Cr-Commit-Position: refs/heads/master@{#413846}
4 files changed