Allow for no samples in test-cpu-profiler/SampleWhenFrameIsNotSetup

test/cctest/test-cpu-profiler.cc

Index: test/cctest/test-cpu-profiler.cc
diff --git a/test/cctest/test-cpu-profiler.cc b/test/cctest/test-cpu-profiler.cc
index 56aa9a7775f00d3459a244295b467a33f4f4ac77..22af9e75b3e3e4135548c3528b31889a41dfe1eb 100644
--- a/test/cctest/test-cpu-profiler.cc
+++ b/test/cctest/test-cpu-profiler.cc
@@ -608,7 +608,9 @@ TEST(SampleWhenFrameIsNotSetup) {
   CheckChildrenNames(root, names);
 
   const v8::CpuProfileNode* startNode = FindChild(root, "start");
-  if (startNode->GetChildrenCount() > 0) {
+  // On slow machines there may be no meaningfull samples at all, skip the
+  // check there.
+  if (startNode && startNode->GetChildrenCount() > 0) {
     CHECK_EQ(1, startNode->GetChildrenCount());
     const v8::CpuProfileNode* delayNode = FindChild(startNode, "delay");
     if (delayNode->GetChildrenCount() > 0) {