Change prealloc number of child FPs be 1 rather than 2"

include/gpu/GrFragmentProcessor.h

Index: include/gpu/GrFragmentProcessor.h
diff --git a/include/gpu/GrFragmentProcessor.h b/include/gpu/GrFragmentProcessor.h
index df6860e981858a831e7681d24416877c9551bad1..55b2f905d9c52e8ebf6adb08b43f2dd81b77eef4 100644
--- a/include/gpu/GrFragmentProcessor.h
+++ b/include/gpu/GrFragmentProcessor.h
@@ -211,7 +211,7 @@ private:
     SkSTArray<4, const GrCoordTransform*, true>     fCoordTransforms;
     int                                             fNumTexturesExclChildren;
     int                                             fNumTransformsExclChildren;
-    SkSTArray<2, const GrFragmentProcessor*, true>  fChildProcessors;
+    SkSTArray<1, const GrFragmentProcessor*, true>  fChildProcessors;
 
     typedef GrProcessor INHERITED;
 };