Fix include guards.

BUG=angle:733

Change-Id: I08b2c11c4831f1161c178c1842b10e807185aced
Reviewed-on: https://chromium-review.googlesource.com/230831
Reviewed-by: Jamie Madill <jmadill@chromium.org>
Tested-by: Geoff Lang <geofflang@chromium.org>
diff --git a/src/compiler/translator/PoolAlloc.h b/src/compiler/translator/PoolAlloc.h
index edd249c..6cd8d30 100644
--- a/src/compiler/translator/PoolAlloc.h
+++ b/src/compiler/translator/PoolAlloc.h
@@ -4,8 +4,8 @@
 // found in the LICENSE file.
 //
 
-#ifndef _POOLALLOC_INCLUDED_
-#define _POOLALLOC_INCLUDED_
+#ifndef COMPILER_TRANSLATOR_POOLALLOC_H_
+#define COMPILER_TRANSLATOR_POOLALLOC_H_
 
 #ifdef _DEBUG
 #define GUARD_BLOCKS  // define to enable guard block sanity checking
@@ -297,4 +297,4 @@
     TPoolAllocator* allocator;
 };
 
-#endif // _POOLALLOC_INCLUDED_
+#endif // COMPILER_TRANSLATOR_POOLALLOC_H_