Fixed up SkTimedPicturePlayback

src/core/SkPictureRangePlayback.cpp

 /*
  * Copyright 2014 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 "SkPictureData.h"
 #include "SkPictureRangePlayback.h"
@@ skipping 11 matching lines @@
         SkASSERT(SAVE_LAYER == op);
         reader.setOffset(fStart + size);
     }
 
     // Record this, so we can concat w/ it if we encounter a setMatrix()
     SkMatrix initialMatrix = canvas->getTotalMatrix();
 
     SkAutoCanvasRestore acr(canvas, false);
 
     while (!reader.eof()) {
-        if (callback && callback->abortDrawing()) {
+        if (NULL != callback && callback->abortDrawing()) {
             return;
         }
 
         if (0 != fStart || 0 != fStop) {
             size_t offset = reader.offset();
             if (offset >= fStop) {
                 SkDEBUGCODE(uint32_t size;)
                 SkDEBUGCODE(DrawType op = ReadOpAndSize(&reader, &size);)
                 SkASSERT(RESTORE == op);
                 return;
             }
         }
 
         fCurOffset = reader.offset();
         uint32_t size;
         DrawType op = ReadOpAndSize(&reader, &size);
         if (NOOP == op) {
             // NOOPs are to be ignored - do not propagate them any further
             reader.setOffset(fCurOffset + size);
             continue;
         }
 
         this->handleOp(&reader, op, size, canvas, initialMatrix);
     }
 }