make allocPixels throw on failure

src/effects/SkAlphaThresholdFilter.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 "SkAlphaThresholdFilter.h"
 #include "SkBitmap.h"
 #include "SkReadBuffer.h"
@@ skipping 323 matching lines @@
     if (!ctx.ctm().invert(&localInverse)) {
         return false;
     }
 
     SkAutoLockPixels alp(src);
     SkASSERT(src.getPixels());
     if (!src.getPixels() || src.width() <= 0 || src.height() <= 0) {
         return false;
     }
 
-    if (!dst->allocPixels(src.info())) {
+    if (!dst->tryAllocPixels(src.info())) {
         return false;
     }
 
     U8CPU innerThreshold = (U8CPU)(fInnerThreshold * 0xFF);
     U8CPU outerThreshold = (U8CPU)(fOuterThreshold * 0xFF);
     SkColor* sptr = src.getAddr32(0, 0);
     SkColor* dptr = dst->getAddr32(0, 0);
     int width = src.width(), height = src.height();
     for (int y = 0; y < height; ++y) {
         for (int x = 0; x < width; ++x) {
@@ skipping 20 matching lines @@
                                                   (U8CPU)(SkColorGetG(source) * scale),
                                                   (U8CPU)(SkColorGetB(source) * scale));
                 }
             }
             dptr[y * dst->width() + x] = output_color;
         }
     }
 
     return true;
 }