ART: Further refactor use lists

Change-Id: I9e3219575a508ca5141d851bfcaf848302480c32
diff --git a/compiler/optimizing/live_ranges_test.cc b/compiler/optimizing/live_ranges_test.cc
index 2097ea6..92742f9 100644
--- a/compiler/optimizing/live_ranges_test.cc
+++ b/compiler/optimizing/live_ranges_test.cc
@@ -432,7 +432,7 @@
   ASSERT_TRUE(range->GetNext() == nullptr);
 
   HPhi* phi = liveness.GetInstructionFromSsaIndex(4)->AsPhi();
-  ASSERT_EQ(phi->ExpensiveComputeNumberOfUses(), 1u);
+  ASSERT_TRUE(phi->GetUses().HasOnlyOneUse());
   interval = phi->GetLiveInterval();
   range = interval->GetFirstRange();
   ASSERT_EQ(26u, range->GetStart());