Fix build warning: reference cannot be bound to dereferenced null pointer in well-defined C++ code;…

src/core/SkPaint.cpp

 /*
  * Copyright 2006 The Android Open Source Project
  *
  * Use of this source code is governed by a BSD-style license that can be
  * found in the LICENSE file.
  */
 
 #include "SkPaint.h"
 #include "SkAnnotation.h"
 #include "SkAutoKern.h"
@@ skipping 98 matching lines @@
 }
 
 SkPaint& SkPaint::operator=(const SkPaint& src) {
     if (this == &src) {
         return *this;
     }
 
 #define COPY(field) field = src.field
 #define REF_COPY(field) SkSafeUnref(field); field = SkSafeRef(src.field)
 
-    SkASSERT(&src);
-
     REF_COPY(fTypeface);
     REF_COPY(fPathEffect);
     REF_COPY(fShader);
     REF_COPY(fXfermode);
     REF_COPY(fMaskFilter);
     REF_COPY(fColorFilter);
     REF_COPY(fRasterizer);
     REF_COPY(fLooper);
     REF_COPY(fImageFilter);
     REF_COPY(fAnnotation);
@@ skipping 2297 matching lines @@
 }
 
 uint32_t SkPaint::getHash() const {
     // We're going to hash 10 pointers and 7 32-bit values, finishing up with fBitfields,
     // so fBitfields should be 10 pointers and 6 32-bit values from the start.
     SK_COMPILE_ASSERT(offsetof(SkPaint, fBitfields) == 10 * sizeof(void*) + 6 * sizeof(uint32_t),
                       SkPaint_notPackedTightly);
     return SkChecksum::Murmur3(reinterpret_cast<const uint32_t*>(this),
                                offsetof(SkPaint, fBitfields) + sizeof(fBitfields));
 }