Fix sky include guards to match Chromium style

sky/engine/platform/testing/TreeTestHelpers.h

 /*
  * Copyright (C) 2010 Google Inc. All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions
  * are met:
  *
  * 1.  Redistributions of source code must retain the above copyright
  *     notice, this list of conditions and the following disclaimer.
  * 2.  Redistributions in binary form must reproduce the above copyright
@@ skipping 10 matching lines @@
  * ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
  * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
  */
 
 // Simple pseudorandom number generator helper functions, used by the
 // red-black and interval tree tests.
 //
 // These are **not** thread safe!
 
-#ifndef TreeTestHelpers_h
-#define TreeTestHelpers_h
+#ifndef SKY_ENGINE_PLATFORM_TESTING_TREETESTHELPERS_H_
+#define SKY_ENGINE_PLATFORM_TESTING_TREETESTHELPERS_H_
 
 #include <stdint.h>
 
 namespace blink {
 namespace TreeTestHelpers {
 
 // Initializes the pseudo-random number generator with a specific seed.
 void initRandom(const int32_t seed);
 
 // Produces the next pseudo-random number in the sequence, in the
 // range from [0..maximumValue). Negative numbers are not allowed and will
 // produce undefined results.
 int32_t nextRandom(const int32_t maximumValue);
 
 } // namespace TreeTestHelpers
 } // namespace blink
 
-#endif // TreeTestHelpers_h
+#endif  // SKY_ENGINE_PLATFORM_TESTING_TREETESTHELPERS_H_