Remove some Isolate::current_zone() calls, as it gets the zone from mutator thread not the current …

runtime/vm/benchmark_test.cc

Index: runtime/vm/benchmark_test.cc
diff --git a/runtime/vm/benchmark_test.cc b/runtime/vm/benchmark_test.cc
index 9fcb4d00fdc85a8a333d58389e7287085f994ba4..1b22bc521a4498b9fa257b00c05b1f95d1b3c13a 100644
--- a/runtime/vm/benchmark_test.cc
+++ b/runtime/vm/benchmark_test.cc
@@ -41,8 +41,7 @@ BENCHMARK(CorelibCompileAll) {
   bin::Builtin::SetNativeResolver(bin::Builtin::kIOLibrary);
   Timer timer(true, "Compile all of Core lib benchmark");
   timer.Start();
-  const Error& error = Error::Handle(benchmark->isolate()->current_zone(),
-                                     Library::CompileAll());
+  const Error& error = Error::Handle(Library::CompileAll());
   if (!error.IsNull()) {
     OS::PrintErr("Unexpected error in CorelibCompileAll benchmark:\n%s",
                  error.ToErrorCString());
@@ -61,8 +60,7 @@ BENCHMARK(CorelibCompilerStats) {
   stats->EnableBenchmark();
   Timer timer(true, "Compiler stats compiling all of Core lib");
   timer.Start();
-  const Error& error = Error::Handle(benchmark->isolate()->current_zone(),
-                                     Library::CompileAll());
+  const Error& error = Error::Handle(Library::CompileAll());
   if (!error.IsNull()) {
     OS::PrintErr("Unexpected error in CorelibCompileAll benchmark:\n%s",
                  error.ToErrorCString());