Reland r18714 'Unify calling to GenerateFastApiCallBody before stubbing it'

src/stub-cache.cc

Index: src/stub-cache.cc
diff --git a/src/stub-cache.cc b/src/stub-cache.cc
index e2558e82cd9af9b28063c6b13ecc6342634b0637..89ed586c642665239ede225cc29de7044c5e4392 100644
--- a/src/stub-cache.cc
+++ b/src/stub-cache.cc
@@ -1994,20 +1994,44 @@ CallOptimization::CallOptimization(Handle<JSFunction> function) {
 }
 
 
-int CallOptimization::GetPrototypeDepthOfExpectedType(
+Handle<Map> CallOptimization::LookupHolderOfExpectedType(
+    Handle<JSObject> receiver,
     Handle<JSObject> object,
-    Handle<JSObject> holder) const {
+    Handle<JSObject> holder,
+    HolderLookup* holder_lookup) const {
   ASSERT(is_simple_api_call());
-  if (expected_receiver_type_.is_null()) return 0;
-  int depth = 0;
+  ASSERT_EQ(kHolderNotFound, *holder_lookup);
+  *holder_lookup = kHolderIsReceiver;
+  Handle<Map> map_to_holder;
+  if (expected_receiver_type_.is_null()) {
+    // no expected type, load from receiver.
+    return map_to_holder;
+  }
+  // walk down the prototype chain to the object
+  while (!receiver.is_identical_to(object)) {
+    *holder_lookup = kHolderIsPrototypeOfMap;
+    map_to_holder = Handle<Map>(receiver->map());
+    receiver = Handle<JSObject>(JSObject::cast(map_to_holder->prototype()));
+  }
+  // start looking for the holder
   while (!object.is_identical_to(holder)) {
-    if (expected_receiver_type_->IsTemplateFor(object->map())) return depth;
-    object = Handle<JSObject>(JSObject::cast(object->GetPrototype()));
-    if (!object->map()->is_hidden_prototype()) return kInvalidProtoDepth;
-    ++depth;
+    Handle<Map> object_map(object->map());
+    if (expected_receiver_type_->IsTemplateFor(*object_map)) {
+      return map_to_holder;
+    }
+    if (!object_map->is_hidden_prototype()) {
+      *holder_lookup = kHolderNotFound;
+      return Handle<Map>::null();
+    }
+    *holder_lookup = kHolderIsPrototypeOfMap;
+    map_to_holder = object_map;
+    object = Handle<JSObject>(JSObject::cast(object_map->prototype()));
+  }
+  if (expected_receiver_type_->IsTemplateFor(holder->map())) {
+    return map_to_holder;
   }
-  if (expected_receiver_type_->IsTemplateFor(holder->map())) return depth;
-  return kInvalidProtoDepth;
+  *holder_lookup = kHolderNotFound;
+  return Handle<Map>::null();
 }