make allocPixels throw on failure

tests/ReadPixelsTest.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 "SkBitmapDevice.h"
 #include "SkCanvas.h"
 #include "SkColorPriv.h"
@@ skipping 78 matching lines @@
         r = SkMulDiv255Ceiling(r, a);
         g = SkMulDiv255Ceiling(g, a);
         b = SkMulDiv255Ceiling(b, a);
     }
     return SkPackARGB32(a, r, g, b);
 }
 
 static void fillCanvas(SkCanvas* canvas) {
     static SkBitmap bmp;
     if (bmp.isNull()) {
-        SkDEBUGCODE(bool alloc =) bmp.allocN32Pixels(DEV_W, DEV_H);
-        SkASSERT(alloc);
-        SkAutoLockPixels alp(bmp);
+        bmp.allocN32Pixels(DEV_W, DEV_H);
         intptr_t pixels = reinterpret_cast<intptr_t>(bmp.getPixels());
         for (int y = 0; y < DEV_H; ++y) {
             for (int x = 0; x < DEV_W; ++x) {
                 SkPMColor* pixel = reinterpret_cast<SkPMColor*>(pixels + y * bmp.rowBytes() + x * bmp.bytesPerPixel());
                 *pixel = getCanvasColor(x, y);
             }
         }
     }
     canvas->save();
     canvas->setMatrix(SkMatrix::I());
@@ skipping 274 matching lines @@
                         checkRead(reporter, wkbmp, clippedRect.fLeft,
                                   clippedRect.fTop, true, false);
                     } else {
                         REPORTER_ASSERT(reporter, !success);
                     }
                 }
             }
         }
     }
 }