Remove some SK_API from src/

There are still some present (being used by Chromium or Android),
but I think all of these are internal-only.

Change-Id: I80177a65e0ea737e88ab7bb1ef36d03edebd4fa4
Reviewed-on: https://skia-review.googlesource.com/c/skia/+/255138
Reviewed-by: Mike Reed <reed@google.com>
Commit-Queue: Brian Osman <brianosman@google.com>
diff --git a/src/pathops/SkPathOpsAsWinding.cpp b/src/pathops/SkPathOpsAsWinding.cpp
index 80e52be..3dfae2f 100644
--- a/src/pathops/SkPathOpsAsWinding.cpp
+++ b/src/pathops/SkPathOpsAsWinding.cpp
@@ -373,7 +373,7 @@
     return true;
 }
 
-bool SK_API AsWinding(const SkPath& path, SkPath* result) {
+bool AsWinding(const SkPath& path, SkPath* result) {
     if (!path.isFinite()) {
         return false;
     }