Have GrMtlTexture and GrMtlRenderTarget call parents onRelease/Abandon.

Bug: skia:
Change-Id: Ib7c19f4a1951f7463912b78c18ed7f2839833193
Reviewed-on: https://skia-review.googlesource.com/c/189485
Commit-Queue: Greg Daniel <egdaniel@google.com>
Reviewed-by: Robert Phillips <robertphillips@google.com>
diff --git a/src/gpu/mtl/GrMtlRenderTarget.mm b/src/gpu/mtl/GrMtlRenderTarget.mm
index 07e5639..4e6cc83 100644
--- a/src/gpu/mtl/GrMtlRenderTarget.mm
+++ b/src/gpu/mtl/GrMtlRenderTarget.mm
@@ -66,11 +66,13 @@
 void GrMtlRenderTarget::onAbandon() {
     fRenderTexture = nil;
     fResolveTexture = nil;
+    INHERITED::onAbandon();
 }
 
 void GrMtlRenderTarget::onRelease() {
     fRenderTexture = nil;
     fResolveTexture = nil;
+    INHERITED::onRelease();
 }
 
 bool GrMtlRenderTarget::completeStencilAttachment() {