Bigger stepping granularity in debugging

runtime/vm/dart_api_impl.cc

 // Copyright (c) 2012, the Dart project authors.  Please see the AUTHORS file
 // for details. All rights reserved. Use of this source code is governed by a
 // BSD-style license that can be found in the LICENSE file.
 
 #include "include/dart_api.h"
 
 #include "vm/bigint_operations.h"
 #include "vm/class_finalizer.h"
 #include "vm/compiler.h"
 #include "vm/dart.h"
@@ skipping 3096 matching lines @@
     RETURN_TYPE_ERROR(isolate, source, String);
   }
   Library& library =
       Library::Handle(isolate, isolate->object_store()->root_library());
   if (!library.IsNull()) {
     const String& library_url = String::Handle(isolate, library.url());
     return Api::NewError("%s: A script has already been loaded from '%s'.",
                          CURRENT_FUNC, library_url.ToCString());
   }
   library = Library::New(url_str);
+  library.set_debuggable(true);
   library.Register();
   isolate->object_store()->set_root_library(library);
   Dart_Handle result;
   CompileSource(isolate,
                 library,
                 url_str,
                 source_str,
                 RawScript::kScript,
                 &result);
   return result;
@@ skipping 20 matching lines @@
     return Api::NewError("%s: A script has already been loaded from '%s'.",
                          CURRENT_FUNC, library_url.ToCString());
   }
   SnapshotReader reader(snapshot, isolate);
   const Object& tmp = Object::Handle(isolate, reader.ReadObject());
   if (!tmp.IsLibrary()) {
     return Api::NewError("%s: Unable to deserialize snapshot correctly.",
                          CURRENT_FUNC);
   }
   library ^= tmp.raw();
+  library.set_debuggable(true);
   isolate->object_store()->set_root_library(library);
   return Api::NewHandle(isolate, library.raw());
 }
 
 
 DART_EXPORT Dart_Handle Dart_RootLibrary() {
   Isolate* isolate = Isolate::Current();
   DARTSCOPE(isolate);
   Library& library =
       Library::Handle(isolate, isolate->object_store()->root_library());
@@ skipping 225 matching lines @@
       *buffer = NULL;
     }
     delete debug_region;
   } else {
     *buffer = NULL;
     *buffer_size = 0;
   }
 }
 
 }  // namespace dart