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

gm/imagefiltersclipped.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 "sk_tool_utils.h"
 #include "SkBitmapSource.h"
 #include "SkBlurImageFilter.h"
@@ skipping 50 matching lines @@
 
     void onDraw(SkCanvas* canvas) override {
         if (!fInitialized) {
             fCheckerboard.allocN32Pixels(64, 64);
             SkCanvas checkerboardCanvas(fCheckerboard);
             sk_tool_utils::draw_checkerboard(&checkerboardCanvas, 0xFFA0A0A0, 0xFF404040, 8);
 
             this->make_gradient_circle(64, 64);
             fInitialized = true;
         }
-        canvas->clear(0x00000000);
+        canvas->clear(SK_ColorBLACK);
 
         SkAutoTUnref<SkImageFilter> gradient(SkBitmapSource::Create(fGradientCircle));
         SkAutoTUnref<SkImageFilter> checkerboard(SkBitmapSource::Create(fCheckerboard));
         SkAutoTUnref<SkShader> noise(SkPerlinNoiseShader::CreateFractalNoise(
             SkDoubleToScalar(0.1), SkDoubleToScalar(0.05), 1, 0));
         SkMatrix resizeMatrix;
         resizeMatrix.setScale(RESIZE_FACTOR_X, RESIZE_FACTOR_Y);
 
         SkImageFilter* filters[] = {
             SkBlurImageFilter::Create(SkIntToScalar(12), SkIntToScalar(12)),
@@ skipping 53 matching lines @@
     SkBitmap fGradientCircle;
     typedef GM INHERITED;
 };
 
 //////////////////////////////////////////////////////////////////////////////
 
 static GM* MyFactory(void*) { return new ImageFiltersClippedGM; }
 static GMRegistry reg(MyFactory);
 
 }