Runtime call counters and timers.

src/runtime/runtime-internal.cc

Index: src/runtime/runtime-internal.cc
diff --git a/src/runtime/runtime-internal.cc b/src/runtime/runtime-internal.cc
index ba20aa392ebe2ad6ba6b48c4beb6af56949e5143..e0783265f0ec9c6113fa7b15bbf15fefa4598f8a 100644
--- a/src/runtime/runtime-internal.cc
+++ b/src/runtime/runtime-internal.cc
@@ -477,5 +477,17 @@ RUNTIME_FUNCTION(Runtime_IncrementUseCounter) {
   return isolate->heap()->undefined_value();
 }
 
+
+RUNTIME_FUNCTION(Runtime_GetAndResetRuntimeCallStats) {
+  HandleScope scope(isolate);
+  DCHECK_EQ(0, args.length());
+  std::stringstream stats_stream;
+  isolate->runtime_state()->runtime_call_stats()->Print(stats_stream);
+  Handle<String> result =
+      isolate->factory()->NewStringFromAsciiChecked(stats_stream.str().c_str());
+  isolate->runtime_state()->runtime_call_stats()->Reset();
+  return *result;
+}
+
 }  // namespace internal
 }  // namespace v8