Initial CL to create GrBatchTest infrastructure

include/gpu/GrTestUtils.h

 /*
  * Copyright 2015 Google Inc.
  *
  * Use of this source code is governed by a BSD-style license that can be
  * found in the LICENSE file.
  */
 
 #ifndef GrTestUtils_DEFINED
 #define GrTestUtils_DEFINED
 
 #include "GrColor.h"
 #include "SkRandom.h"
 
 class SkMatrix;
+class SkRect;
 
 namespace GrTest {
 /**
  * A helper for use in Test functions.
  */
 const SkMatrix& TestMatrix(SkRandom*);
+const SkRect& TestRect(SkRandom*);
 
 }
 
 static inline GrColor GrRandomColor(SkRandom* random) {
     // There are only a few cases of random colors which interest us
     enum ColorMode {
         kAllOnes_ColorMode,
         kAllZeros_ColorMode,
         kAlphaOne_ColorMode,
         kRandom_ColorMode,
@@ skipping 44 matching lines @@
             coverage = 0xff;
             break;
         case kRandom_CoverageMode:
             coverage = random->nextULessThan(256);
             break;
     }
     return coverage;
 }
 
 #endif