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

tools/skpdiff/SkDiffContext.h

 /*
  * Copyright 2013 Google Inc.
  *
  * Use of this source code is governed by a BSD-style license that can be
  * found in the LICENSE file.
  */
 
 #ifndef SkDiffContext_DEFINED
 #define SkDiffContext_DEFINED
 
 #include "SkImageDiffer.h"
-#include "SkMutex.h"
 #include "SkString.h"
 #include "SkTArray.h"
 #include "SkTDArray.h"
 #include "SkTLList.h"
+#include "SkThread.h"
 
 class SkWStream;
 
 /**
  * Collects records of diffs and outputs them as JSON.
  */
 class SkDiffContext {
 public:
     SkDiffContext();
     ~SkDiffContext();
@@ skipping 18 matching lines @@
 
     /**
      * Sets the directory within which to store whiteDiffs (images showing white
      * for each pixel that differs between baseline and test).
      *
      * If the directory does not exist yet, it will be created.
      */
     void setWhiteDiffDir(const SkString& directory);
 
     /**
-     * Modify the pattern used to generate commonName (= the
+     * Modify the pattern used to generate commonName (= the 
      * basename of rgb/white diff files).
      *
      * - true: basename is a combination of the input file names.
      * - false: basename is the common prefix of the input file names.
      *
      * For example, for:
      *   baselinePath=/tmp/dir/image-before.png
      *   testPath=/tmp/dir/image-after.png
-     *
+     * 
      * If setLongNames(true), commonName would be:
      *    image-before-png-vs-image-after-png.png
-     *
+     * 
      * If setLongNames(false), commonName would be:
      *   image-.png
      */
     void setLongNames(const bool useLongNames);
 
     /**
      * Sets the differs to be used in each diff. Already started diffs will not retroactively use
      * these.
      * @param differs An array of differs to use. The array is copied, but not the differs
      *                themselves.
@@ skipping 19 matching lines @@
      * @param baselinePath The baseline file path
      * @param testPath     The matching test file path
      */
     void addDiff(const char* baselinePath, const char* testPath);
 
     /**
      * Output the records of each diff in JSON.
      *
      * The format of the JSON document is one top level array named "records".
      * Each record in the array is an object with the following values:
-     *    "commonName"     : string containing the output filename (basename)
-     *                       depending on the value of 'longNames'.
+     *    "commonName"     : string containing the output filename (basename) 
+     *                       depending on the value of 'longNames'. 
      *                       (see 'setLongNames' for an explanation and example).
      *    "baselinePath"   : string containing the path to the baseline image
      *    "testPath"       : string containing the path to the test image
      *    "differencePath" : (optional) string containing the path to an alpha
      *                       mask of the pixel difference between the baseline
      *                       and test images
      *                       TODO(epoger): consider renaming this "alphaMaskPath"
      *                       to distinguish from other difference types?
      *    "rgbDiffPath"    : (optional) string containing the path to a bitmap
      *                       showing per-channel differences between the
@@ skipping 75 matching lines @@
     int fDifferCount;
     int fThreadCount;
 
     SkString fAlphaMaskDir;
     SkString fRgbDiffDir;
     SkString fWhiteDiffDir;
     bool longNames;
 };
 
 #endif