allow tests to optionally use multiple threads

tests/Test.h

 
 /*
  * Copyright 2011 Google Inc.
  *
  * Use of this source code is governed by a BSD-style license that can be
  * found in the LICENSE file.
  */
 #ifndef skiatest_Test_DEFINED
 #define skiatest_Test_DEFINED
 
@@ skipping 25 matching lines @@
         int countTests() const { return fTestCount; }
         int countResults(Result r) {
             SkASSERT((unsigned)r <= kLastResult);
             return fResultCount[r];
         }
 
         void startTest(Test*);
         void report(const char testDesc[], Result);
         void endTest(Test*);
         virtual bool allowExtendedTest() const { return false; }
-
+        virtual bool allowThreaded() const { return false; }
         // helpers for tests
         void assertTrue(bool cond, const char desc[]) {
             if (!cond) {
                 this->report(desc, kFailed);
             }
         }
         void assertFalse(bool cond, const char desc[]) {
             if (cond) {
                 this->report(desc, kFailed);
             }
@@ skipping 71 matching lines @@
     do {                                                                     \
         if (!(cond)) {                                                       \
             SkString desc;                                                   \
             desc.printf("%s %s:%d: %s", message, __FILE__, __LINE__, #cond); \
             r->reportFailed(desc);                                           \
         }                                                                    \
     } while(0)
 
 
 #endif