Dump out path-mask generation and caching stats

These stats would've helped block https://skia-review.googlesource.com/c/skia/+/286902 (Add path bounds to SW path mask key) from landing.

Change-Id: I684f39de53fb2678c7a679e4e4aafdbb39a154ca
Reviewed-on: https://skia-review.googlesource.com/c/skia/+/287499
Reviewed-by: Brian Salomon <bsalomon@google.com>
Commit-Queue: Robert Phillips <robertphillips@google.com>
diff --git a/src/gpu/GrSoftwarePathRenderer.cpp b/src/gpu/GrSoftwarePathRenderer.cpp
index 36994fc..20850f8 100644
--- a/src/gpu/GrSoftwarePathRenderer.cpp
+++ b/src/gpu/GrSoftwarePathRenderer.cpp
@@ -321,6 +321,7 @@
             GrSwizzle swizzle = args.fRenderTargetContext->caps()->getReadSwizzle(
                     proxy->backendFormat(), GrColorType::kAlpha_8);
             view = {std::move(proxy), kTopLeft_GrSurfaceOrigin, swizzle};
+            args.fContext->priv().stats()->incNumPathMasksCacheHits();
         }
     }
     if (!view) {
@@ -378,6 +379,8 @@
             fProxyProvider->assignUniqueKeyToProxy(maskKey, view.asTextureProxy());
             args.fShape->addGenIDChangeListener(std::move(listener));
         }
+
+        args.fContext->priv().stats()->incNumPathMasksGenerated();
     }
     SkASSERT(view);
     if (inverseFilled) {