[heap] Expand verification of layout changes to non-JSObject objects.

src/objects.cc

Index: src/objects.cc
diff --git a/src/objects.cc b/src/objects.cc
index 0fcf13ff77de7ace052790d96bba962383c7b315..62e27c482381197d3d13054a49241559d79f2d7a 100644
--- a/src/objects.cc
+++ b/src/objects.cc
@@ -2475,6 +2475,7 @@ Handle<String> String::SlowFlatten(Handle<ConsString> cons,
 
 
 bool String::MakeExternal(v8::String::ExternalStringResource* resource) {
+  DisallowHeapAllocation no_allocation;
   // Externalizing twice leaks the external resource, so it's
   // prohibited by the API.
   DCHECK(!this->IsExternalString());
@@ -2497,7 +2498,9 @@ bool String::MakeExternal(v8::String::ExternalStringResource* resource) {
   bool is_one_byte = this->IsOneByteRepresentation();
   bool is_internalized = this->IsInternalizedString();
   bool has_pointers = StringShape(this).IsIndirect();
-
+  if (has_pointers) {
+    heap->NotifyObjectLayoutChange(this, no_allocation);
+  }
   // Morph the string to an external string by replacing the map and
   // reinitializing the fields.  This won't work if the space the existing
   // string occupies is too small for a regular  external string.
@@ -2543,6 +2546,7 @@ bool String::MakeExternal(v8::String::ExternalStringResource* resource) {
 
 
 bool String::MakeExternal(v8::String::ExternalOneByteStringResource* resource) {
+  DisallowHeapAllocation no_allocation;
   // Externalizing twice leaks the external resource, so it's
   // prohibited by the API.
   DCHECK(!this->IsExternalString());
@@ -2570,6 +2574,10 @@ bool String::MakeExternal(v8::String::ExternalOneByteStringResource* resource) {
   bool is_internalized = this->IsInternalizedString();
   bool has_pointers = StringShape(this).IsIndirect();
 
+  if (has_pointers) {
+    heap->NotifyObjectLayoutChange(this, no_allocation);
+  }
+
   // Morph the string to an external string by replacing the map and
   // reinitializing the fields.  This won't work if the space the existing
   // string occupies is too small for a regular  external string.
@@ -17392,6 +17400,7 @@ void MakeStringThin(String* string, String* internalized, Isolate* isolate) {
 
   if (!string->IsInternalizedString()) {
     DisallowHeapAllocation no_gc;
+    isolate->heap()->NotifyObjectLayoutChange(string, no_gc);
     bool one_byte = internalized->IsOneByteRepresentation();
     Handle<Map> map = one_byte ? isolate->factory()->thin_one_byte_string_map()
                                : isolate->factory()->thin_string_map();