Make SkSmallAllocator obey the RAII invariants and be expandable

src/core/SkRasterPipelineBlitter.cpp

Index: src/core/SkRasterPipelineBlitter.cpp
diff --git a/src/core/SkRasterPipelineBlitter.cpp b/src/core/SkRasterPipelineBlitter.cpp
index b8c0107e262fd916b28a52ea6051a2bb19ce2fac..4d1fecc483a8eee7884ab1afdd49a882d109ddc2 100644
--- a/src/core/SkRasterPipelineBlitter.cpp
+++ b/src/core/SkRasterPipelineBlitter.cpp
@@ -99,8 +99,7 @@ SkBlitter* SkRasterPipelineBlitter::Create(const SkPixmap& dst,
                                                            paint.getBlendMode(),
                                                            paint_color(dst, paint));
     auto earlyOut = [&] {
-        blitter->~SkRasterPipelineBlitter();
-        alloc->freeLast();
+        alloc->deleteLast();
         return nullptr;
     };