Quieten the "invoking/returned" and "Visiting stack roots" logging.

Change-Id: I51de60f7baee64a378ca811749e63d5dc2bc9221
diff --git a/src/object.cc b/src/object.cc
index 33cd802..506c2c8 100644
--- a/src/object.cc
+++ b/src/object.cc
@@ -651,9 +651,14 @@
 #endif
 
   if (have_executable_code && stub != NULL) {
-    LOG(INFO) << "invoking " << PrettyMethod(this) << " code=" << (void*) GetCode() << " stub=" << (void*) stub;
+    bool log = false;
+    if (log) {
+      LOG(INFO) << "invoking " << PrettyMethod(this) << " code=" << (void*) GetCode() << " stub=" << (void*) stub;
+    }
     (*stub)(this, receiver, self, args, result);
-    LOG(INFO) << "returned " << PrettyMethod(this) << " code=" << (void*) GetCode() << " stub=" << (void*) stub;
+    if (log) {
+      LOG(INFO) << "returned " << PrettyMethod(this) << " code=" << (void*) GetCode() << " stub=" << (void*) stub;
+    }
   } else {
     if (Runtime::Current()->IsStarted()) {
       LOG(WARNING) << "Not invoking method with no associated code: " << PrettyMethod(this);