Fix http://dartbug.com/23578:

runtime/vm/intermediate_language_mips.cc

Index: runtime/vm/intermediate_language_mips.cc
diff --git a/runtime/vm/intermediate_language_mips.cc b/runtime/vm/intermediate_language_mips.cc
index 4e279c5937780e4f8da451d6e886b3940167c87a..b26ab1681f6d30f09b34da542efea8e938023aff 100644
--- a/runtime/vm/intermediate_language_mips.cc
+++ b/runtime/vm/intermediate_language_mips.cc
@@ -24,7 +24,6 @@
 namespace dart {
 
 DECLARE_FLAG(bool, emit_edge_counters);
-DECLARE_FLAG(bool, enable_asserts);
 DECLARE_FLAG(int, optimization_counter_threshold);
 DECLARE_FLAG(bool, use_osr);
 
@@ -427,11 +426,11 @@ static void EmitAssertBoolean(Register reg,
   ASSERT(locs->always_calls());
   Label done;
 
-  if (Isolate::Current()->TypeChecksEnabled()) {
+  if (Isolate::Current()->flags().type_checks()) {
     __ BranchEqual(reg, Bool::True(), &done);
     __ BranchEqual(reg, Bool::False(), &done);
   } else {
-    ASSERT(FLAG_enable_asserts);
+    ASSERT(Isolate::Current()->flags().asserts());
     __ BranchNotEqual(reg, Object::null_instance(), &done);
   }