optimizing: Refactor statistics to use OptimizingCompilerStats helper

Remove all copies of 'MaybeRecordStat', replacing them with a single
OptimizingCompilerStats::MaybeRecordStat helper.

Change-Id: I83b96b41439dccece3eee2e159b18c95336ea933
diff --git a/compiler/optimizing/optimizing_compiler_stats.h b/compiler/optimizing/optimizing_compiler_stats.h
index a211c54..098d23d 100644
--- a/compiler/optimizing/optimizing_compiler_stats.h
+++ b/compiler/optimizing/optimizing_compiler_stats.h
@@ -216,6 +216,14 @@
   DISALLOW_COPY_AND_ASSIGN(OptimizingCompilerStats);
 };
 
+inline void MaybeRecordStat(OptimizingCompilerStats* compiler_stats,
+                            MethodCompilationStat stat,
+                            uint32_t count = 1) {
+  if (compiler_stats != nullptr) {
+    compiler_stats->RecordStat(stat, count);
+  }
+}
+
 }  // namespace art
 
 #endif  // ART_COMPILER_OPTIMIZING_OPTIMIZING_COMPILER_STATS_H_