Move precompilation-related flags to flags list.

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 488a2d918da432540c506dca731fc8566e60e38e..1c59f8dbea52baec1fe3415f98e60df98d225161 100644
--- a/runtime/vm/benchmark_test.cc
+++ b/runtime/vm/benchmark_test.cc
@@ -20,8 +20,6 @@ using dart::bin::File;
 
 namespace dart {
 
-DECLARE_FLAG(bool, background_compilation);
-
 Benchmark* Benchmark::first_ = NULL;
 Benchmark* Benchmark::tail_ = NULL;
 const char* Benchmark::executable_ = NULL;
@@ -181,10 +179,15 @@ BENCHMARK(Dart2JSCompilerStats) {
   stats->EnableBenchmark();
   Timer timer(true, "Compile all of dart2js benchmark");
   timer.Start();
+#if !defined(PRODUCT)
+  // Constant in product mode.
   const bool old_flag = FLAG_background_compilation;
   FLAG_background_compilation = false;
+#endif
   Dart_Handle result = Dart_CompileAll();
+#if !defined(PRODUCT)
   FLAG_background_compilation = old_flag;
+#endif
   EXPECT_VALID(result);
   timer.Stop();
   int64_t elapsed_time = timer.TotalElapsedTime();
@@ -387,10 +390,14 @@ BENCHMARK(Dart2JSCompileAll) {
   }
   Timer timer(true, "Compile all of dart2js benchmark");
   timer.Start();
+#if !defined(PRODUCT)
   const bool old_flag = FLAG_background_compilation;
   FLAG_background_compilation = false;
+#endif
   Dart_Handle result = Dart_CompileAll();
+#if !defined(PRODUCT)
   FLAG_background_compilation = old_flag;
+#endif
   EXPECT_VALID(result);
   timer.Stop();
   int64_t elapsed_time = timer.TotalElapsedTime();