Make sampling heap profiler work for short living scripts.

src/profiler/sampling-heap-profiler.cc

Index: src/profiler/sampling-heap-profiler.cc
diff --git a/src/profiler/sampling-heap-profiler.cc b/src/profiler/sampling-heap-profiler.cc
index b38643cf1a3a67e1516146219fd4ef86a9c12ae4..b2bba7010bfde256aa3990d2753272f5c81c9a97 100644
--- a/src/profiler/sampling-heap-profiler.cc
+++ b/src/profiler/sampling-heap-profiler.cc
@@ -204,15 +204,17 @@ v8::AllocationProfile::Node* SamplingHeapProfiler::TranslateAllocationNode(
     // Cannot use std::map<T>::at because it is not available on android.
     auto non_const_scripts = const_cast<std::map<int, Script*>&>(scripts);
     Script* script = non_const_scripts[node->script_id_];
-    if (script->name()->IsName()) {
-      Name* name = Name::cast(script->name());
-      script_name = ToApiHandle<v8::String>(
-          isolate_->factory()->InternalizeUtf8String(names_->GetName(name)));
+    if (script) {
+      if (script->name()->IsName()) {
+        Name* name = Name::cast(script->name());

[Michael Achenbach, 2016/03/24 09:18:25]

Experimental code-coverage reports this block as not executed on x64. I see
three cases:
1) Is there really no test that exercises this, then please consider adding a v8
stand-alone test.
2) Is it executed in some other configuration? No action required.
3) It is executed in some test on x64? Then code coverage has a bug.

+        script_name = ToApiHandle<v8::String>(
+            isolate_->factory()->InternalizeUtf8String(names_->GetName(name)));
+      }
+      Handle<Script> script_handle(script);
+      line = 1 + Script::GetLineNumber(script_handle, node->script_position_);
+      column =
+          1 + Script::GetColumnNumber(script_handle, node->script_position_);
     }
-    Handle<Script> script_handle(script);
-
-    line = 1 + Script::GetLineNumber(script_handle, node->script_position_);
-    column = 1 + Script::GetColumnNumber(script_handle, node->script_position_);
     for (auto alloc : node->allocations_) {
       allocations.push_back(ScaleSample(alloc.first, alloc.second));
     }