Replace our homegrown ARRAY_SIZE() with Chrome's arraysize().

src/arm64/instrument-arm64.cc

Index: src/arm64/instrument-arm64.cc
diff --git a/src/arm64/instrument-arm64.cc b/src/arm64/instrument-arm64.cc
index 59982d975bcf4c70ff996bec0309aca1ea3016f0..da505ff294b834847dc2f2a3cf8390fd035bc090 100644
--- a/src/arm64/instrument-arm64.cc
+++ b/src/arm64/instrument-arm64.cc
@@ -107,7 +107,7 @@ Instrument::Instrument(const char* datafile, uint64_t sample_period)
     }
   }
 
-  static const int num_counters = ARRAY_SIZE(kCounterList);
+  static const int num_counters = arraysize(kCounterList);
 
   // Dump an instrumentation description comment at the top of the file.
   fprintf(output_stream_, "# counters=%d\n", num_counters);