make allocPixels throw on failure

src/core/SkScalerContext.cpp

 
 /*
  * Copyright 2006 The Android Open Source Project
  *
  * Use of this source code is governed by a BSD-style license that can be
  * found in the LICENSE file.
  */
 
 
 #include "SkScalerContext.h"
@@ skipping 419 matching lines @@
             SkDEBUGFAIL("unexpected mask format");
     }
 
     SkRasterClip clip;
     clip.setRect(SkIRect::MakeWH(dstW, dstH));
 
     const SkImageInfo info = SkImageInfo::MakeA8(dstW, dstH);
     SkBitmap bm;
 
     if (0 == dstRB) {
-        if (!bm.allocPixels(info)) {
+        if (!bm.tryAllocPixels(info)) {
             // can't allocate offscreen, so empty the mask and return
             sk_bzero(mask.fImage, mask.computeImageSize());
             return;
         }
     } else {
         bm.installPixels(info, mask.fImage, dstRB);
     }
     sk_bzero(bm.getPixels(), bm.getSafeSize());
 
     SkDraw  draw;
@@ skipping 341 matching lines @@
 SkScalerContext* SkTypeface::createScalerContext(const SkDescriptor* desc,
                                                  bool allowFailure) const {
     SkScalerContext* c = this->onCreateScalerContext(desc);
 
     if (!c && !allowFailure) {
         c = SkNEW_ARGS(SkScalerContext_Empty,
                        (const_cast<SkTypeface*>(this), desc));
     }
     return c;
 }