Increase safety of PictureTest

tests/PictureTest.cpp

 /*
  * Copyright 2012 Google Inc.
  *
  * Use of this source code is governed by a BSD-style license that can be
  * found in the LICENSE file.
  */
 #include "Test.h"
 #include "SkCanvas.h"
 #include "SkColorPriv.h"
 #include "SkData.h"
@@ skipping 171 matching lines @@
         SkAutoTUnref<SkPicture> pic(record_bitmaps(bm, pos, N, procs[k]));
 
         // quick check for a small piece of each quadrant, which should just
         // contain 1 bitmap.
         for (size_t  i = 0; i < SK_ARRAY_COUNT(pos); ++i) {
             SkRect r;
             r.set(2, 2, W - 2, H - 2);
             r.offset(pos[i].fX, pos[i].fY);
             SkAutoDataUnref data(SkPictureUtils::GatherPixelRefs(pic, r));
             REPORTER_ASSERT(reporter, data);
-            int count = data->size() / sizeof(SkPixelRef*);
-            REPORTER_ASSERT(reporter, 1 == count);
-            REPORTER_ASSERT(reporter, *(SkPixelRef**)data->data() == refs[i]);
+            if (data) {
+                int count = data->size() / sizeof(SkPixelRef*);
+                REPORTER_ASSERT(reporter, 1 == count);
+                REPORTER_ASSERT(reporter, *(SkPixelRef**)data->data() == refs[i]);
+            }
         }
 
         // Test a bunch of random (mostly) rects, and compare the gather results
         // with a deduced list of refs by looking at the colors drawn.
         for (int j = 0; j < 100; ++j) {
             SkRect r;
             rand_rect(&r, rand, 2*W, 2*H);
 
             SkBitmap result;
             draw(pic, r, &result);
@@ skipping 352 matching lines @@
 #endif
     test_peephole();
     test_gatherpixelrefs(reporter);
     test_bitmap_with_encoded_data(reporter);
     test_clone_empty(reporter);
     test_clip_bound_opt(reporter);
 }
 
 #include "TestClassDef.h"
 DEFINE_TESTCLASS("Pictures", PictureTestClass, TestPicture)