[heap] introduce ArrayBufferTracker

src/api.cc

Index: src/api.cc
diff --git a/src/api.cc b/src/api.cc
index 2cb41a09215ebfe985786c06e2fc35442aa72dff..3e6958fae8351f30e55c6b62f46bdbc1657d9f80 100644
--- a/src/api.cc
+++ b/src/api.cc
@@ -6509,8 +6509,7 @@ v8::ArrayBuffer::Contents v8::ArrayBuffer::Externalize() {
   Utils::ApiCheck(!self->is_external(), "v8::ArrayBuffer::Externalize",
                   "ArrayBuffer already externalized");
   self->set_is_external(true);
-  isolate->heap()->UnregisterArrayBuffer(isolate->heap()->InNewSpace(*self),
-                                         self->backing_store());
+  isolate->heap()->UnregisterArrayBuffer(*self);
 
   return GetContents();
 }
@@ -6719,8 +6718,7 @@ v8::SharedArrayBuffer::Contents v8::SharedArrayBuffer::Externalize() {
   Utils::ApiCheck(!self->is_external(), "v8::SharedArrayBuffer::Externalize",
                   "SharedArrayBuffer already externalized");
   self->set_is_external(true);
-  isolate->heap()->UnregisterArrayBuffer(isolate->heap()->InNewSpace(*self),
-                                         self->backing_store());
+  isolate->heap()->UnregisterArrayBuffer(*self);
   return GetContents();
 }