add legacy/helper allocN32Pixels, and convert gm to use it

gm/drawbitmaprect.cpp

 
 /*
  * Copyright 2011 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 "SkBlurMask.h"
 #include "SkBlurMaskFilter.h"
 #include "SkColorPriv.h"
 #include "SkGradientShader.h"
 #include "SkShader.h"
 
 namespace skiagm {
 
 static SkBitmap make_chessbm(int w, int h) {
     SkBitmap bm;
-    bm.setConfig(SkBitmap::kARGB_8888_Config , w, h);
-    bm.allocPixels();
+    bm.allocN32Pixels(w, h);
 
     for (int y = 0; y < bm.height(); y++) {
         uint32_t* p = bm.getAddr32(0, y);
         for (int x = 0; x < bm.width(); x++) {
             p[x] = ((x + y) & 1) ? SK_ColorWHITE : SK_ColorBLACK;
         }
     }
     bm.unlockPixels();
     return bm;
 }
 
 static void makebm(SkBitmap* bm, SkBitmap::Config config, int w, int h) {
-    bm->setConfig(config, w, h);
-    bm->allocPixels();
+    bm->allocConfigPixels(config, w, h);
     bm->eraseColor(SK_ColorTRANSPARENT);
 
     SkCanvas    canvas(*bm);
 
     SkScalar wScalar = SkIntToScalar(w);
     SkScalar hScalar = SkIntToScalar(h);
 
     SkPoint     pt = { wScalar / 2, hScalar / 2 };
 
     SkScalar    radius = 4 * SkMaxScalar(wScalar, hScalar);
@@ skipping 135 matching lines @@
     typedef GM INHERITED;
 };
 
 //////////////////////////////////////////////////////////////////////////////
 
 #ifndef SK_BUILD_FOR_ANDROID
 static GM* MyFactory(void*) { return new DrawBitmapRectGM; }
 static GMRegistry reg(MyFactory);
 #endif
 }