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/gm/strokes.cpp b/gm/strokes.cpp
index 77638e4..7382390 100644
--- a/gm/strokes.cpp
+++ b/gm/strokes.cpp
@@ -1,4 +1,3 @@
-
 /*
  * Copyright 2011 Google Inc.
  *
@@ -6,9 +5,8 @@
  * found in the LICENSE file.
  */
 
-
-
 #include "gm.h"
+#include "SkPath.h"
 #include "SkRandom.h"
 
 #define W   400