Removed instances of fprintf in run_vm_tests and replaced them with OS::Print/PrintErr.

runtime/bin/run_vm_tests.cc

Index: runtime/bin/run_vm_tests.cc
diff --git a/runtime/bin/run_vm_tests.cc b/runtime/bin/run_vm_tests.cc
index 8d49fe077baff3d1feec009fd5d437758e65f3ea..784ee990d337c1998d216e05f76324f279e288b6 100644
--- a/runtime/bin/run_vm_tests.cc
+++ b/runtime/bin/run_vm_tests.cc
@@ -35,16 +35,16 @@ static int run_matches = 0;
 
 
 void TestCase::Run() {
-  fprintf(stdout, "Running test: %s\n", name());
+  OS::Print("Running test: %s\n", name());
   (*run_)();
-  fprintf(stdout, "Done: %s\n", name());
+  OS::Print("Done: %s\n", name());
 }
 
 
 void RawTestCase::Run() {
-  fprintf(stdout, "Running test: %s\n", name());
+  OS::Print("Running test: %s\n", name());
   (*run_)();
-  fprintf(stdout, "Done: %s\n", name());
+  OS::Print("Done: %s\n", name());
 }
 
 
@@ -53,7 +53,7 @@ void TestCaseBase::RunTest() {
     this->Run();
     run_matches++;
   } else if (run_filter == kList) {
-    fprintf(stdout, "%s\n", this->name());
+    OS::Print("%s\n", this->name());
     run_matches++;
   }
 }
@@ -67,18 +67,18 @@ void Benchmark::RunBenchmark() {
               this->score());
     run_matches++;
   } else if (run_filter == kList) {
-    fprintf(stdout, "%s\n", this->name());
+    OS::Print("%s\n", this->name());
     run_matches++;
   }
 }
 
 
 static void PrintUsage() {
-  fprintf(stderr,
-          "run_vm_tests [--list | --benchmarks | "
-          "<test name> | <benchmark name>]\n");
-  fprintf(stderr, "run_vm_tests [vm-flags ...] <test name>\n");
-  fprintf(stderr, "run_vm_tests [vm-flags ...] <benchmark name>\n");
+  OS::PrintErr(
+      "run_vm_tests [--list | --benchmarks | "
+      "<test name> | <benchmark name>]\n");
+  OS::PrintErr("run_vm_tests [vm-flags ...] <test name>\n");
+  OS::PrintErr("run_vm_tests [vm-flags ...] <benchmark name>\n");
 }
 
 
@@ -133,7 +133,7 @@ static int Main(int argc, const char** argv) {
   TestCaseBase::RunAllRaw();
   // Print a warning message if no tests or benchmarks were matched.
   if (run_matches == 0) {
-    fprintf(stderr, "No tests matched: %s\n", run_filter);
+    OS::PrintErr("No tests matched: %s\n", run_filter);
     return 1;
   }
   if (DynamicAssertionHelper::failed()) {