Fix sky include guards to match Chromium style

sky/engine/wtf/DefaultAllocator.h

 /*
  * Copyright (C) 2013 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:
  *
  *     * Redistributions of source code must retain the above copyright
  * notice, this list of conditions and the following disclaimer.
  *     * Redistributions in binary form must reproduce the above
@@ skipping 10 matching lines @@
  * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
  * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
  * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
  * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
  * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND 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.
  */
 
-#ifndef WTF_DefaultAllocator_h
-#define WTF_DefaultAllocator_h
+#ifndef SKY_ENGINE_WTF_DEFAULTALLOCATOR_H_
+#define SKY_ENGINE_WTF_DEFAULTALLOCATOR_H_
 
 // This is the allocator that is used for allocations that are not on the
 // traced, garbage collected heap. It uses FastMalloc for collections,
 // but uses the partition allocator for the backing store of the collections.
 
 #include "sky/engine/wtf/Assertions.h"
 #include "sky/engine/wtf/FastAllocBase.h"
 #include "sky/engine/wtf/PartitionAlloc.h"
 #include "sky/engine/wtf/WTF.h"
 
@@ skipping 138 matching lines @@
     void* operator new(size_t, NotNullTag, void* location) \
     { \
         ASSERT(location); \
         return location; \
     } \
 private: \
 typedef int __thisIsHereToForceASemicolonAfterThisMacro
 
 using WTF::DefaultAllocator;
 
-#endif // WTF_DefaultAllocator_h
+#endif  // SKY_ENGINE_WTF_DEFAULTALLOCATOR_H_