[PathKit] Write more complete docs and clean up API to be consistent

Breaking Changes (should be minor, as it's mostly just things
for testing):
 - PathKit.ApplyPathOp should have returned a new SkPath, but didn't.
It now does and is named "MakeFromOp", which makes the convention of
"Have 'make' in name, needs delete" more consistent.
 - PathKit.FromCmds(arr) now only needs to take the JS Array and
will handle the TypedArrays under the hood. If clients want to deal
with TypedArrays themselves, they can use _FromCmds(ptr, len) directly.
 - PathKit.MakeLTRBRect is now just PathKit.LTRBRect. The thing
returned is a normal JS Object and doesn't need delete().

As per custom with v0 apps, we are updating the minor version
to v0.3.0 to account for breaking changes.


Docs-Preview: https://skia.org/?cl=147960
Bug: skia:8216
Change-Id: Ia3626e69f3e97698fc62a6aee876af005e29ffca
Reviewed-on: https://skia-review.googlesource.com/147960
Reviewed-by: Mike Reed <reed@google.com>
Reviewed-by: Heather Miller <hcm@google.com>
diff --git a/experimental/pathkit/tests/svg.spec.js b/experimental/pathkit/tests/svg.spec.js
index c28618b..ca3afe2 100644
--- a/experimental/pathkit/tests/svg.spec.js
+++ b/experimental/pathkit/tests/svg.spec.js
@@ -45,8 +45,7 @@
                        [PathKit.LINE_VERB, 5, 295],
                        [PathKit.LINE_VERB, 205, 5],
                        [PathKit.CLOSE_VERB]];
-            let [ptr, len] = PathKit.loadCmdsTypedArray(cmds);
-            let path = PathKit.FromCmds(ptr, len);
+            let path = PathKit.FromCmds(cmds);
 
             let svgStr = path.toSVGString();
             // We output it in terse form, which is different than Wikipedia's version
@@ -64,8 +63,7 @@
                        [PathKit.LINE_VERB, 5, 295],
                        [PathKit.LINE_VERB, "0x15e80300", "0x400004dc"], // 9.37088e-26f, 2.0003f
                        [PathKit.CLOSE_VERB]];
-            let [ptr, len] = PathKit.loadCmdsTypedArray(cmds);
-            let path = PathKit.FromCmds(ptr, len);
+            let path = PathKit.FromCmds(cmds);
 
             let svgStr = path.toSVGString();
             expect(svgStr).toEqual('M9.37088e-26 2.0003L795 5L595 295L5 295L9.37088e-26 2.0003Z');