Ensure playing back a picture always balances saves and restores

src/core/SkPicturePlayback.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 <new>
 #include "SkBBoxHierarchy.h"
 #include "SkPicturePlayback.h"
 #include "SkPictureRecord.h"
@@ skipping 841 matching lines @@
     if (it.isValid()) {
         uint32_t skipTo = it.nextDraw();
         if (kDrawComplete == skipTo) {
             return;
         }
         reader.setOffset(skipTo);
     }
 
     // Record this, so we can concat w/ it if we encounter a setMatrix()
     SkMatrix initialMatrix = canvas.getTotalMatrix();
-    int originalSaveCount = canvas.getSaveCount();
+
+    SkAutoCanvasRestore acr(&canvas, false);
 
 #ifdef SK_BUILD_FOR_ANDROID
     fAbortCurrentPlayback = false;
 #endif
 
 #ifdef SK_DEVELOPER
     int opIndex = -1;
 #endif
 
     while (!reader.eof()) {
         if (callback && callback->abortDrawing()) {
-            canvas.restoreToCount(originalSaveCount);
             return;
         }
 #ifdef SK_BUILD_FOR_ANDROID
         if (fAbortCurrentPlayback) {
             return;
         }
 #endif
         if (0 != fStart || 0 != fStop) {
             size_t offset = reader.offset() ;
             if (offset >= fStop) {
@@ skipping 953 matching lines @@
     for (index = 0; index < fPictureCount; index++)
         bufferPtr += snprintf(bufferPtr, DUMP_BUFFER_SIZE - (bufferPtr - pBuffer),
             "picture%p, ", fPictureRefs[index]);
     if (fPictureCount > 0)
         SkDebugf("%s0};\n", pBuffer);
 
     const_cast<SkPicturePlayback*>(this)->dumpStream();
 }
 
 #endif