Take care fall-through case of switch in skia

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
 
@@ skipping 73 matching lines @@
         kAllOnes_CoverageMode,
         kRandom_CoverageMode,
         kLast_CoverageMode = kRandom_CoverageMode
     };
 
     CoverageMode colorMode = CoverageMode(random->nextULessThan(kLast_CoverageMode + 1));
     uint8_t coverage;
     switch (colorMode) {
         case kZero_CoverageMode:
             coverage = 0;
+            break;
         case kAllOnes_CoverageMode:
             coverage = 0xff;
             break;
         case kRandom_CoverageMode:
             coverage = random->nextULessThan(256);
             break;
     }
     return coverage;
 }
 
 #endif
 #endif