[PathKit] Add more Path2D functionality and move some methods to be members

Adds arc, arcTo, rect and Path2D names for quadTo, cubicTo, close.

Adds conic verb support (approximated with 2 quads).

Breaking changes:
Some functions have been moved to be member functions:
PathKit.Simplify(path) -> path.simplify()
PathKit.ToCanvas(path, ctx) -> path.toCanvas(ctx)
PathKit.ToSVGString(path) -> path.toSVGString()
PathKit.ToPath2D(path) -> path.toPath2D()
PathKit.ToCmds(path) -> path.toCmds()
PathKit.ResolveBuilder(builder) -> builder.resolve()
PathKit.GetBoundaryPathFromRegion(region) -> region.getBoundaryPath()

Pathkit.ApplyPathOp(pathOne, pathTwo, op) still exists, but there's
now also pathOne.op(pathTwo, op) for cases when that's easier.

As per custom with version 0.x.y projects, I'm bumping the
minor version (in npm) for these breaking changes instead of the
major version (which will happen when we are version >= 1.0.0).

This also has some small improvements to the output code size.
The biggest jump was from enabling the closure compiler on the
helper JS, which trimmed it down by about 40%. Using the closure
compiler requires the JRE on the bots, which prompted the emsdk-base
image change.

Bug: skia:8216
Change-Id: I40902d23380093c34d1679df0255bcb0eaa77b01
Reviewed-on: https://skia-review.googlesource.com/145420
Reviewed-by: Joe Gregorio <jcgregorio@google.com>
Reviewed-by: Florin Malita <fmalita@chromium.org>
11 files changed