Introduce an API mirroring the gc extension

src/api.cc

 // Copyright 2012 the V8 project authors. All rights reserved.
 // Redistribution and use in source and binary forms, with or without
 // modification, are permitted provided that the following conditions are
 // met:
 //
 //     * Redistributions of source code must retain the above copyright
 //       notice, this list of conditions and the following disclaimer.
 //     * Redistributions in binary form must reproduce the above
 //       copyright notice, this list of conditions and the following
 //       disclaimer in the documentation and/or other materials provided
@@ skipping 6434 matching lines @@
   reinterpret_cast<i::Isolate*>(this)->stack_guard()->RequestInterrupt(
       callback, data);
 }
 
 
 void Isolate::ClearInterrupt() {
   reinterpret_cast<i::Isolate*>(this)->stack_guard()->ClearInterrupt();
 }
 
 
+void Isolate::RequestGarbageCollectionForTesting(GarbageCollectionType type) {
+  CHECK(i::FLAG_expose_gc);
+  if (type == kMinorGarbageCollection) {
+    reinterpret_cast<i::Isolate*>(this)->heap()->CollectGarbage(
+        i::NEW_SPACE, "Isolate::RequestGarbageCollection");
+  } else {
+    ASSERT_EQ(kFullGarbageCollection, type);
+    reinterpret_cast<i::Isolate*>(this)->heap()->CollectAllGarbage(
+        i::Heap::kNoGCFlags, "Isolate::RequestGarbageCollection");
+  }
+}
+
+
 Isolate* Isolate::GetCurrent() {
   i::Isolate* isolate = i::Isolate::UncheckedCurrent();
   return reinterpret_cast<Isolate*>(isolate);
 }
 
 
 Isolate* Isolate::New() {
   i::Isolate* isolate = new i::Isolate();
   return reinterpret_cast<Isolate*>(isolate);
 }
@@ skipping 993 matching lines @@
   Isolate* isolate = reinterpret_cast<Isolate*>(info.GetIsolate());
   Address callback_address =
       reinterpret_cast<Address>(reinterpret_cast<intptr_t>(callback));
   VMState<EXTERNAL> state(isolate);
   ExternalCallbackScope call_scope(isolate, callback_address);
   callback(info);
 }
 
 
 } }  // namespace v8::internal