make allocPixels throw on failure

tests/ImageDecodingTest.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 "Resources.h"
 #include "SkBitmap.h"
 #include "SkCanvas.h"
@@ skipping 752 matching lines @@
     ~SingleAllocator() {}
     // If the pixels in fPixels are big enough, use them.
     virtual bool allocPixelRef(SkBitmap* bm, SkColorTable* ct) SK_OVERRIDE {
         SkASSERT(bm);
         if (bm->info().getSafeSize(bm->rowBytes()) <= fSize) {
             bm->setPixels(fPixels, ct);
             fPixels = NULL;
             fSize = 0;
             return true;
         }
-        return bm->allocPixels(NULL, ct);
+        return bm->tryAllocPixels(NULL, ct);
     }
     bool ready() { return fPixels != NULL; }
 private:
     void* fPixels;
     size_t fSize;
 };
 }  // namespace
 
 /*  This tests for a bug in libjpeg where INT32 is typedefed to long
     and memory can be written to outside of the array. */
@@ skipping 26 matching lines @@
                        ((void*)pixels.get(), sizeof(uint16_t) * pixelCount)));
     decoder->setAllocator(allocator);
     decoder->setSampleSize(2);
     SkBitmap bitmap;
     bool success = decoder->decode(stream, &bitmap, kRGB_565_SkColorType,
                                    SkImageDecoder::kDecodePixels_Mode);
     REPORTER_ASSERT(r, success);
     REPORTER_ASSERT(r, !allocator->ready());  // Decoder used correct memory
     REPORTER_ASSERT(r, sentinal == pixels[pixelCount]);
 }