Remove more uses of Isolate::current_zone.

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 b701c0e28a4deab358e5b16cedf0e4fb55997ca3..052011af06a0134e79ee1c84c544aad95536ad49 100644
--- a/runtime/vm/dart_api_impl.cc
+++ b/runtime/vm/dart_api_impl.cc
@@ -1773,19 +1773,20 @@ DART_EXPORT Dart_Port Dart_GetMainPortId() {
 // --- Scopes ----
 
 DART_EXPORT void Dart_EnterScope() {
-  Isolate* isolate = Isolate::Current();
+  Thread* thread = Thread::Current();
+  Isolate* isolate = thread->isolate();
   CHECK_ISOLATE(isolate);
   ApiState* state = isolate->api_state();
   ASSERT(state != NULL);
   ApiLocalScope* new_scope = state->reusable_scope();
   if (new_scope == NULL) {
     new_scope = new ApiLocalScope(state->top_scope(),
-                                  isolate->top_exit_frame_info());
+                                  thread->top_exit_frame_info());
     ASSERT(new_scope != NULL);
   } else {
-    new_scope->Reinit(isolate,
+    new_scope->Reinit(thread,
                       state->top_scope(),
-                      isolate->top_exit_frame_info());
+                      thread->top_exit_frame_info());
     state->set_reusable_scope(NULL);
   }
   state->set_top_scope(new_scope);  // New scope is now the top scope.
@@ -1793,14 +1794,15 @@ DART_EXPORT void Dart_EnterScope() {
 
 
 DART_EXPORT void Dart_ExitScope() {
-  Isolate* isolate = Isolate::Current();
+  Thread* thread = Thread::Current();
+  Isolate* isolate = thread->isolate();
   CHECK_ISOLATE_SCOPE(isolate);
   ApiState* state = isolate->api_state();
   ApiLocalScope* scope = state->top_scope();
   ApiLocalScope* reusable_scope = state->reusable_scope();
   state->set_top_scope(scope->previous());  // Reset top scope to previous.
   if (reusable_scope == NULL) {
-    scope->Reset(isolate);  // Reset the old scope which we just exited.
+    scope->Reset(thread);  // Reset the old scope which we just exited.
     state->set_reusable_scope(scope);
   } else {
     ASSERT(reusable_scope != scope);