GM: some header cleanup

gm.h includes sk_tool_utils.h but does not use it.

The bulk of this CL makes each gm that uses sk_tool_utils include it.

sk_tool_utils.h also provided SkRandom and SkTDArray,
so a couple GMs add those headers too.

Change-Id: Ieb2a7c542f0ca89c3223f744fc11b0ff37af36c1
Reviewed-on: https://skia-review.googlesource.com/10014
Commit-Queue: Mike Klein <mtklein@chromium.org>
Reviewed-by: Herb Derby <herb@google.com>
diff --git a/gm/clip_error.cpp b/gm/clip_error.cpp
index 28f7432..0a3eceb 100644
--- a/gm/clip_error.cpp
+++ b/gm/clip_error.cpp
@@ -6,6 +6,7 @@
  */
 
 #include "gm.h"
+#include "sk_tool_utils.h"
 #include "SkBlurMask.h"
 #include "SkBlurMaskFilter.h"
 #include "SkCanvas.h"