replace setConfig+allocPixels with single call

tests/EmptyPathTest.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 "SkCanvas.h"
 #include "SkPath.h"
 #include "Test.h"
 
 #define DIMENSION   32
 
 static void drawAndTest(skiatest::Reporter* reporter, const SkPath& path,
                         const SkPaint& paint, bool shouldDraw) {
     SkBitmap bm;
-    // explicitly specify a trim rowbytes, so we have no padding on each row
-    bm.setConfig(SkBitmap::kARGB_8888_Config, DIMENSION, DIMENSION, DIMENSION*4);
-    bm.allocPixels();
+    bm.allocN32Pixels(DIMENSION, DIMENSION);
+    SkASSERT(DIMENSION*4 == bm.rowBytes()); // ensure no padding on each row
     bm.eraseColor(SK_ColorTRANSPARENT);
 
     SkCanvas canvas(bm);
     SkPaint p(paint);
     p.setColor(SK_ColorWHITE);
 
     canvas.drawPath(path, p);
 
     size_t count = DIMENSION * DIMENSION;
     const SkPMColor* ptr = bm.getAddr32(0, 0);
@@ skipping 103 matching lines @@
                 bool shouldDraw = path.isInverseFillType();
                 iter_paint(reporter, path, shouldDraw);
             }
         }
     }
 }
 
 DEF_TEST(EmptyPath, reporter) {
     test_emptydrawing(reporter);
 }