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

include/gpu/GrFragmentProcessor.h

 /*
  * Copyright 2014 Google Inc.
  *
  * Use of this source code is governed by a BSD-style license that can be
  * found in the LICENSE file.
  */
 
 #ifndef GrFragmentProcessor_DEFINED
 #define GrFragmentProcessor_DEFINED
 
@@ skipping 193 matching lines @@
      *                          /             /    \
      *                        /             /        \
      *                      (C)          (E)          (F)
      *                     [c1]      [e1,e2,e3]      [f1,f2]
      *
      * The same goes for fTextureAccesses with textures.
      */
     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;
 };
 
 #endif