Bugfix that cause skpdiff to segfault.

tools/skpdiff/SkDiffContext.cpp

Index: tools/skpdiff/SkDiffContext.cpp
diff --git a/tools/skpdiff/SkDiffContext.cpp b/tools/skpdiff/SkDiffContext.cpp
index 78d84009687424447f6f791b4ecea57d8c665789..4248ca3b560a9438c8df867eaa68a1b91332d640 100644
--- a/tools/skpdiff/SkDiffContext.cpp
+++ b/tools/skpdiff/SkDiffContext.cpp
@@ -289,6 +289,7 @@ void SkDiffContext::diffPatterns(const char baselinePattern[], const char testPa
         runnableDiffs[x].setup(this, baselineEntries[x], testEntries[x]);
         tg.add(&runnableDiffs[x]);
     }
+    tg.wait();

[stephana, 2014/09/05 17:03:20]

This line should not be necessary, because wait() is called in the destructor of
SkTaskGroup and therefore should be called when 'tg' goes out of scope.

[mtklein, 2014/09/05 17:18:51]

I agree.  So why does it fix the crash?

 }
 
 void SkDiffContext::outputRecords(SkWStream& stream, bool useJSONP) {