Be less aggressive in sharing contexts between scopes so that sibling contexts

runtime/vm/object_test.cc

Index: runtime/vm/object_test.cc
===================================================================
--- runtime/vm/object_test.cc	(revision 44591)
+++ runtime/vm/object_test.cc	(working copy)
@@ -2473,17 +2473,13 @@
   const int first_parameter_index = 0;
   const int num_parameters = 0;
   const int first_frame_index = -1;
-  LocalScope* loop_owner = parent_scope;
-  LocalScope* context_owner = NULL;   // No context allocated yet.
   bool found_captured_vars = false;
   int next_frame_index = parent_scope->AllocateVariables(first_parameter_index,
                                                          num_parameters,
                                                          first_frame_index,
-                                                         loop_owner,
-                                                         &context_owner,
+                                                         NULL,
                                                          &found_captured_vars);
   EXPECT_EQ(first_frame_index, next_frame_index);  // a and c not in frame.
-  EXPECT_EQ(parent_scope, context_owner);  // parent_scope allocated a context.
   const intptr_t parent_scope_context_level = 1;
   EXPECT_EQ(parent_scope_context_level, parent_scope->context_level());
   EXPECT(found_captured_vars);