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

src/core/SkShader.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 "SkAtomics.h"
 #include "SkBitmapProcShader.h"
 #include "SkColorShader.h"
 #include "SkEmptyShader.h"
+#include "SkReadBuffer.h"
 #include "SkMallocPixelRef.h"
 #include "SkPaint.h"
 #include "SkPicture.h"
 #include "SkPictureShader.h"
-#include "SkReadBuffer.h"
 #include "SkScalar.h"
 #include "SkShader.h"
+#include "SkThread.h"
 #include "SkWriteBuffer.h"
 
 //#define SK_TRACK_SHADER_LIFETIME
 
 #ifdef SK_TRACK_SHADER_LIFETIME
     static int32_t gShaderCounter;
 #endif
 
 static inline void inc_shader_counter() {
 #ifdef SK_TRACK_SHADER_LIFETIME
@@ skipping 360 matching lines @@
 #include "SkEmptyShader.h"
 
 void SkEmptyShader::toString(SkString* str) const {
     str->append("SkEmptyShader: (");
 
     this->INHERITED::toString(str);
 
     str->append(")");
 }
 #endif