Profiling fixes

runtime/vm/thread_test.cc

Index: runtime/vm/thread_test.cc
diff --git a/runtime/vm/thread_test.cc b/runtime/vm/thread_test.cc
index ff8b5635278352075d8365bb9a50d983c4ca035a..1305a1c51b3c2ad0d6d606ed0b03fdb0712274a2 100644
--- a/runtime/vm/thread_test.cc
+++ b/runtime/vm/thread_test.cc
@@ -5,6 +5,7 @@
 #include "platform/assert.h"
 #include "vm/isolate.h"
 #include "vm/unit_test.h"
+#include "vm/signal_handler.h"
 #include "vm/thread.h"
 
 namespace dart {
@@ -42,6 +43,10 @@ UNIT_TEST_CASE(Monitor) {
   const int kNumAttempts = 5;
   int attempts = 0;
   while (attempts < kNumAttempts) {
+    // This test verifies that a monitor returns after the specified timeout. If
+    // a signal is delivered to this thread, the monitor may return early.
+    // Block signal delivery in this scope.
+    ScopedSignalBlocker ssb;
     MonitorLocker ml(monitor);
     int64_t start = OS::GetCurrentTimeMillis();
     int64_t wait_time = 2017;