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

gm/downsamplebitmap.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 "SkGradientShader.h"
 
@@ skipping 81 matching lines @@
       DownsampleBitmapTextGM(float textSize, SkPaint::FilterLevel filterLevel)
       : INHERITED(filterLevel), fTextSize(textSize)
         {
             fName.printf("downsamplebitmap_text_%s_%.2fpt", this->filterLevelToString(), fTextSize);
         }
 
   protected:
       float fTextSize;
 
       virtual void make_bitmap() SK_OVERRIDE {
-          fBM.setConfig(SkBitmap::kARGB_8888_Config, int(fTextSize * 8), int(fTextSize * 6));
-          fBM.allocPixels();
+          fBM.allocN32Pixels(int(fTextSize * 8), int(fTextSize * 6));
           SkCanvas canvas(fBM);
           canvas.drawColor(SK_ColorWHITE);
 
           SkPaint paint;
           paint.setAntiAlias(true);
           paint.setSubpixelText(true);
           paint.setTextSize(fTextSize);
 
           setTypeface(&paint, "Times", SkTypeface::kNormal);
           canvas.drawText("Hamburgefons", 12, fTextSize/2, 1.2f*fTextSize, paint);
@@ skipping 14 matching lines @@
       : INHERITED(filterLevel), fSize(size), fNumChecks(numChecks)
         {
             fName.printf("downsamplebitmap_checkerboard_%s_%d_%d", this->filterLevelToString(), fSize, fNumChecks);
         }
 
   protected:
       int fSize;
       int fNumChecks;
 
       virtual void make_bitmap() SK_OVERRIDE {
-          fBM.setConfig(SkBitmap::kARGB_8888_Config, fSize, fSize);
-          fBM.allocPixels();
-          SkAutoLockPixels lock(fBM);
+          fBM.allocN32Pixels(fSize, fSize);
           for (int y = 0; y < fSize; ++y) {
               for (int x = 0; x < fSize; ++x) {
                   SkPMColor* s = fBM.getAddr32(x, y);
                   int cx = (x * fNumChecks) / fSize;
                   int cy = (y * fNumChecks) / fSize;
                   if ((cx+cy)%2) {
                       *s = 0xFFFFFFFF;
                   } else {
                       *s = 0xFF000000;
                   }
@@ skipping 25 matching lines @@
           SkFILEStream stream(path.c_str());
           if (stream.isValid()) {
               codec = SkImageDecoder::Factory(&stream);
           }
           if (codec) {
               stream.rewind();
               codec->decode(&stream, &fBM, SkBitmap::kARGB_8888_Config,
                   SkImageDecoder::kDecodePixels_Mode);
               SkDELETE(codec);
           } else {
-              fBM.setConfig(SkBitmap::kARGB_8888_Config, 1, 1);
-              fBM.allocPixels();
+              fBM.allocN32Pixels(1, 1);
               *(fBM.getAddr32(0,0)) = 0xFF0000FF; // red == bad
           }
           fSize = fBM.height();
       }
   private:
       typedef DownsampleBitmapGM INHERITED;
 };
 
 //////////////////////////////////////////////////////////////////////////////
 
 DEF_GM( return new DownsampleBitmapTextGM(72, SkPaint::kHigh_FilterLevel); )
 DEF_GM( return new DownsampleBitmapCheckerboardGM(512,256, SkPaint::kHigh_FilterLevel); )
 DEF_GM( return new DownsampleBitmapImageGM("mandrill_512.png", SkPaint::kHigh_FilterLevel); )
 
 DEF_GM( return new DownsampleBitmapTextGM(72, SkPaint::kMedium_FilterLevel); )
 DEF_GM( return new DownsampleBitmapCheckerboardGM(512,256, SkPaint::kMedium_FilterLevel); )
 DEF_GM( return new DownsampleBitmapImageGM("mandrill_512.png", SkPaint::kMedium_FilterLevel); )
 
 DEF_GM( return new DownsampleBitmapTextGM(72, SkPaint::kLow_FilterLevel); )
 DEF_GM( return new DownsampleBitmapCheckerboardGM(512,256, SkPaint::kLow_FilterLevel); )
 DEF_GM( return new DownsampleBitmapImageGM("mandrill_512.png", SkPaint::kLow_FilterLevel); )
 
 DEF_GM( return new DownsampleBitmapTextGM(72, SkPaint::kNone_FilterLevel); )
 DEF_GM( return new DownsampleBitmapCheckerboardGM(512,256, SkPaint::kNone_FilterLevel); )
 DEF_GM( return new DownsampleBitmapImageGM("mandrill_512.png", SkPaint::kNone_FilterLevel); )