Fix background compilation issues when creating snapshots.

runtime/vm/dart_api_impl.cc

Index: runtime/vm/dart_api_impl.cc
diff --git a/runtime/vm/dart_api_impl.cc b/runtime/vm/dart_api_impl.cc
index 01ed58accef6608c1cda1b02d640abeeefdc0ca4..4dcdeb92fff22900715c35aac68924a732591851 100644
--- a/runtime/vm/dart_api_impl.cc
+++ b/runtime/vm/dart_api_impl.cc
@@ -1483,6 +1483,10 @@ DART_EXPORT Dart_Handle Dart_CreateSnapshot(
     return state;
   }
   I->heap()->CollectAllGarbage();
+  if (I->background_compiler() != NULL) {
+    BackgroundCompiler::Stop(I->background_compiler());
+  }

[siva, 2016/04/04 22:45:38]

I was thinking of adding an Isolate::StopBackgroundCompiler method which did
that and you could call it here and in Isolate::Shutdown

[srdjan, 2016/04/04 23:22:49]

Done.

+
 #if defined(DEBUG)
   FunctionVisitor check_canonical(T);
   I->heap()->IterateObjects(&check_canonical);