spin off easy stuff from Herb's windows GN CL

gm/roundrects.cpp

 /*
  * Copyright 2013 Google Inc.
  *
  * Use of this source code is governed by a BSD-style license that can be
  * found in the LICENSE file.
  */
 
 #include "gm.h"
 #include "SkTArray.h"
 #include "SkRandom.h"
 #include "SkMatrix.h"
 #include "SkBlurMaskFilter.h"
+#include "SkColorFilter.h"
 #include "SkGradientShader.h"
 #include "SkBlurDrawLooper.h"
 #include "SkRect.h"
 #include "SkRRect.h"
 
 namespace skiagm {
 
 static SkColor gen_color(SkRandom* rand) {
     SkScalar hsv[3];
     hsv[0] = rand->nextRangeF(0.0f, 360.0f);
@@ skipping 321 matching lines @@
 
     typedef GM INHERITED;
 };
 
 //////////////////////////////////////////////////////////////////////////////
 
 static GM* MyFactory(void*) { return new RoundRectGM; }
 static GMRegistry reg(MyFactory);
 
 }