IWYU: 'core' target, files starting A-C.

TBR=reed@google.com
Verbal lgtm, does not change API.

Committed: https://skia.googlesource.com/skia/+/7403d87db8e43d4c2b5b25ac22a0ebc22bd09d69

Review URL: https://codereview.chromium.org/1265033002
diff --git a/bench/SKPBench.h b/bench/SKPBench.h
index e1c66bf..05b5857 100644
--- a/bench/SKPBench.h
+++ b/bench/SKPBench.h
@@ -11,6 +11,9 @@
 #include "Benchmark.h"
 #include "SkCanvas.h"
 #include "SkPicture.h"
+#include "SkTDArray.h"
+
+class SkSurface;
 
 /**
  * Runs an SkPicture as a benchmark by repeatedly drawing it scaled inside a device clip.