Writing to testName and reading its size isn't thread safe.

tests/PathOpsExtendedTest.cpp

 /*
  * Copyright 2012 Google Inc.
  *
  * Use of this source code is governed by a BSD-style license that can be
  * found in the LICENSE file.
  */
 
 #include "PathOpsExtendedTest.h"
 #include "PathOpsThreadedCommon.h"
 #include "SkBitmap.h"
@@ skipping 614 matching lines @@
 bool testThreadedPathOp(skiatest::Reporter* reporter, const SkPath& a, const SkPath& b,
                  const SkPathOp shapeOp, const char* testName) {
     return innerPathOp(reporter, a, b, shapeOp, testName, true);
 }
 
 int initializeTests(skiatest::Reporter* reporter, const char* test) {
 #ifdef SK_DEBUG
     SkPathOpsDebug::gMaxWindSum = 4;
     SkPathOpsDebug::gMaxWindValue = 4;
 #endif
+#if DEBUG_SHOW_TEST_NAME
     testName = test;
     size_t testNameSize = strlen(test);
     SkFILEStream inFile("../../experimental/Intersection/op.htm");
     if (inFile.isValid()) {
         SkTDArray<char> inData;
         inData.setCount(inFile.getLength());
         size_t inLen = inData.count();
         inFile.read(inData.begin(), inLen);
         inFile.setPath(NULL);
         char* insert = strstr(inData.begin(), marker);
         if (insert) {
             insert += sizeof(marker) - 1;
             const char* numLoc = insert + 4 /* indent spaces */ + testNameSize - 1;
             testNumber = atoi(numLoc) + 1;
         }
     }
+#endif
     return reporter->allowThreaded() ? SkThreadPool::kThreadPerCore : 1;
 }
 
 void outputProgress(char* ramStr, const char* pathStr, SkPath::FillType pathFillType) {
     const char testFunction[] = "testSimplify(path);";
     const char* pathPrefix = NULL;
     const char* nameSuffix = NULL;
     if (pathFillType == SkPath::kEvenOdd_FillType) {
         pathPrefix = "    path.setFillType(SkPath::kEvenOdd_FillType);\n";
         nameSuffix = "x";
@@ skipping 37 matching lines @@
         }
         if (tests[index].fun == stopTest) {
             SkDebugf("lastTest\n");
         }
         if (index == last) {
             break;
         }
         index += reverse ? -1 : 1;
     } while (true);
 }