Remove offset to SkMallocPixelRef::NewWithData - use SkData::NewSubset instead.

tests/MallocPixelRefTest.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 "SkData.h"
 #include "SkMallocPixelRef.h"
 #include "Test.h"
@@ skipping 86 matching lines @@
                                           delete_uint8_proc, NULL));
         REPORTER_ASSERT(reporter, addr == pr->pixels());
     }
     {
         void* addr = sk_malloc_throw(size);
         SkAutoDataUnref data(SkData::NewFromMalloc(addr, size));
         REPORTER_ASSERT(reporter, data.get() != NULL);
         SkData* dataPtr = data.get();
         REPORTER_ASSERT(reporter, dataPtr->unique());
         SkAutoTUnref<SkMallocPixelRef> pr(
-            SkMallocPixelRef::NewWithData(info, rowBytes, NULL, data.get(), 4));
+            SkMallocPixelRef::NewWithData(info, rowBytes, NULL, data.get()));
         REPORTER_ASSERT(reporter, !(dataPtr->unique()));
         data.reset(NULL);
         REPORTER_ASSERT(reporter, dataPtr->unique());
-        REPORTER_ASSERT(reporter,
-            static_cast<const void*>(dataPtr->bytes() + 4) == pr->pixels());
+        REPORTER_ASSERT(reporter, dataPtr->data() == pr->pixels());
     }
 }