Revert of Remove SkThread.h, include SkMutex.h or SkAtomics.h as appropriate.

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"
 #include "SkChecksum.h"
 #include "SkColorFilter.h"
 #include "SkData.h"
 #include "SkDraw.h"
 #include "SkFontDescriptor.h"
 #include "SkGlyphCache.h"
 #include "SkImageFilter.h"
 #include "SkMaskFilter.h"
 #include "SkMaskGamma.h"
-#include "SkMutex.h"
 #include "SkReadBuffer.h"
 #include "SkWriteBuffer.h"
 #include "SkPaintDefaults.h"
 #include "SkPathEffect.h"
 #include "SkRasterizer.h"
 #include "SkScalar.h"
 #include "SkScalerContext.h"
 #include "SkShader.h"
 #include "SkStringUtils.h"
 #include "SkStroke.h"
@@ skipping 2386 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));
 }