Started using Dart_CreateInGroup when using spawn on a release build.

Author: gaaclarke

runtime/dart_isolate.cc

@@ -251,23 +251,43 @@ std::weak_ptr<DartIsolate> DartIsolate::CreateRootIsolate(
   DartErrorString error;
   Dart_Isolate vm_isolate = nullptr;
   auto isolate_flags = flags.Get();
-  /// TODO(b/72025) This will be where we call Dart_CreateIsolateInGroup if
-  /// spawning_isolate != nullptr.
-  vm_isolate = CreateDartIsolateGroup(
-      std::move(isolate_group_data), std::move(isolate_data), &isolate_flags,
-      error.error(),
-      [](std::shared_ptr<DartIsolateGroupData>* isolate_group_data,
-         std::shared_ptr<DartIsolate>* isolate_data, Dart_IsolateFlags* flags,
-         char** error) {
-        return Dart_CreateIsolateGroup(
-            (*isolate_group_data)->GetAdvisoryScriptURI().c_str(),
-            (*isolate_group_data)->GetAdvisoryScriptEntrypoint().c_str(),
-            (*isolate_group_data)->GetIsolateSnapshot()->GetDataMapping(),
-            (*isolate_group_data)
-                ->GetIsolateSnapshot()
-                ->GetInstructionsMapping(),
-            flags, isolate_group_data, isolate_data, error);
-      });
+
+  IsolateMaker isolate_maker;
+#if FLUTTER_RUNTIME_MODE == FLUTTER_RUNTIME_MODE_PROFILE || \
+    FLUTTER_RUNTIME_MODE == FLUTTER_RUNTIME_MODE_RELEASE
+  if (spawning_isolate) {
+    isolate_maker =  [spawning_isolate](
+            std::shared_ptr<DartIsolateGroupData>* isolate_group_data,
+            std::shared_ptr<DartIsolate>* isolate_data,
+            Dart_IsolateFlags* flags, char** error) {
+      return Dart_CreateIsolateInGroup(
+          /*group_member=*/spawning_isolate->isolate(),
+          /*name=*/"spawn",
+          /*shutdown_callback=*/nullptr,
+          /*cleanup_callback=*/nullptr,
+          /*child_isolate_data=*/isolate_data,
+          /*error=*/error);
+        });
+  }
+#endif
+
+  if (!isolate_maker) {
+    isolate_maker = [](std::shared_ptr<DartIsolateGroupData>*
+                           isolate_group_data,
+                       std::shared_ptr<DartIsolate>* isolate_data,
+                       Dart_IsolateFlags* flags, char** error) {
+      return Dart_CreateIsolateGroup(
+          (*isolate_group_data)->GetAdvisoryScriptURI().c_str(),
+          (*isolate_group_data)->GetAdvisoryScriptEntrypoint().c_str(),
+          (*isolate_group_data)->GetIsolateSnapshot()->GetDataMapping(),
+          (*isolate_group_data)->GetIsolateSnapshot()->GetInstructionsMapping(),
+          flags, isolate_group_data, isolate_data, error);
+    };
+  }
+
+  vm_isolate = CreateDartIsolateGroup(std::move(isolate_group_data),
+                                      std::move(isolate_data), &isolate_flags,
+                                      error.error(), isolate_maker);
 
   if (error) {
     FML_LOG(ERROR) << "CreateRootIsolate failed: " << error.str();
@@ -992,10 +1012,7 @@ Dart_Isolate DartIsolate::CreateDartIsolateGroup(
     std::unique_ptr<std::shared_ptr<DartIsolate>> isolate_data,
     Dart_IsolateFlags* flags,
     char** error,
-    std::function<Dart_Isolate(std::shared_ptr<DartIsolateGroupData>*,
-                               std::shared_ptr<DartIsolate>*,
-                               Dart_IsolateFlags*,
-                               char**)> make_isolate) {
+    const DartIsolate::IsolateMaker& make_isolate) {
   TRACE_EVENT0("flutter", "DartIsolate::CreateDartIsolateGroup");
 
   // Create the Dart VM isolate and give it the embedder object as the baton.

runtime/dart_isolate.h

@@ -517,15 +517,18 @@ class DartIsolate : public UIDartState {
       Dart_IsolateFlags* flags,
       char** error);
 
+  typedef std::function<Dart_Isolate(std::shared_ptr<DartIsolateGroupData>*,
+                                     std::shared_ptr<DartIsolate>*,
+                                     Dart_IsolateFlags*,
+                                     char**)>
+      IsolateMaker;
+
   static Dart_Isolate CreateDartIsolateGroup(
       std::unique_ptr<std::shared_ptr<DartIsolateGroupData>> isolate_group_data,
       std::unique_ptr<std::shared_ptr<DartIsolate>> isolate_data,
       Dart_IsolateFlags* flags,
       char** error,
-      std::function<Dart_Isolate(std::shared_ptr<DartIsolateGroupData>*,
-                                 std::shared_ptr<DartIsolate>*,
-                                 Dart_IsolateFlags*,
-                                 char**)> make_isolate);
+      const IsolateMaker& make_isolate);
 
   static bool InitializeIsolate(std::shared_ptr<DartIsolate> embedder_isolate,
                                 Dart_Isolate isolate,