Change some more GMs to clear to opaque black, not transparent black.

gm/matriximagefilter.cpp

 /*
  * Copyright 2014 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 "SkColor.h"
 #include "SkImageFilter.h"
@@ skipping 40 matching lines @@
                 canvas.drawRect(SkRect::MakeXYWH(0, 0, 16, 16), darkPaint);
                 canvas.drawRect(SkRect::MakeXYWH(16, 0, 16, 16), lightPaint);
                 canvas.drawRect(SkRect::MakeXYWH(0, 16, 16, 16), lightPaint);
                 canvas.drawRect(SkRect::MakeXYWH(16, 16, 16, 16), darkPaint);
                 canvas.restore();
             }
         }
     }
 
     virtual void onDraw(SkCanvas* canvas) {
-        canvas->clear(0x00000000);
+        canvas->clear(SK_ColorBLACK);
         SkMatrix matrix;
         SkScalar margin = SkIntToScalar(10);
         matrix.setSkew(SkDoubleToScalar(0.5), SkDoubleToScalar(0.2));
         SkBitmap checkerboard;
         make_checkerboard(&checkerboard);
 
         SkRect srcRect = SkRect::MakeWH(96, 96);
 
         canvas->translate(margin, margin);
         draw(canvas, srcRect, checkerboard, matrix, kNone_SkFilterQuality);
@@ skipping 14 matching lines @@
 private:
     typedef GM INHERITED;
 };
 
 //////////////////////////////////////////////////////////////////////////////
 
 static GM* MyFactory(void*) { return new MatrixImageFilterGM; }
 static GMRegistry reg(MyFactory);
 
 }