Reland: Plugin Placeholders: Refactor for platforms that don't support plugins

gin/wrappable.cc

 // Copyright 2013 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "gin/wrappable.h"
 
-#include "base/logging.h"
 #include "gin/object_template_builder.h"
 #include "gin/per_isolate_data.h"
 
 namespace gin {
 
 WrappableBase::WrappableBase() {
 }
 
 WrappableBase::~WrappableBase() {
   wrapper_.Reset();
@@ skipping 11 matching lines @@
   data.SetSecondPassCallback(SecondWeakCallback);
 }
 
 void WrappableBase::SecondWeakCallback(
     const v8::WeakCallbackInfo<WrappableBase>& data) {
   WrappableBase* wrappable = data.GetParameter();
   delete wrappable;
 }
 
 v8::Local<v8::Object> WrappableBase::GetWrapperImpl(v8::Isolate* isolate,
-                                                     WrapperInfo* info) {
+                                                    WrapperInfo* info) {
   if (!wrapper_.IsEmpty()) {
     return v8::Local<v8::Object>::New(isolate, wrapper_);
   }
 
   PerIsolateData* data = PerIsolateData::From(isolate);
   v8::Local<v8::ObjectTemplate> templ = data->GetObjectTemplate(info);
   if (templ.IsEmpty()) {
     templ = GetObjectTemplateBuilder(isolate).Build();
     CHECK(!templ.IsEmpty());
     data->SetObjectTemplate(info, templ);
   }
   CHECK_EQ(kNumberOfInternalFields, templ->InternalFieldCount());
   v8::Local<v8::Object> wrapper;
   // |wrapper| may be empty in some extreme cases, e.g., when
   // Object.prototype.constructor is overwritten.
   if (!templ->NewInstance(isolate->GetCurrentContext()).ToLocal(&wrapper)) {
     // The current wrappable object will be no longer managed by V8. Delete this
     // now.
     delete this;
     return wrapper;
   }
   wrapper->SetAlignedPointerInInternalField(kWrapperInfoIndex, info);
+  // This needs to be adjusted with downcasting on retrieval, as this points
+  // to the WrapperBase object, which may not be the start of the whole object.
   wrapper->SetAlignedPointerInInternalField(kEncodedValueIndex, this);
   wrapper_.Reset(isolate, wrapper);
   wrapper_.SetWeak(this, FirstWeakCallback, v8::WeakCallbackType::kParameter);
   return wrapper;
 }
 
-namespace internal {
-
-void* FromV8Impl(v8::Isolate* isolate, v8::Local<v8::Value> val,
-                 WrapperInfo* wrapper_info) {
-  if (!val->IsObject())
-    return NULL;
-  v8::Local<v8::Object> obj = v8::Local<v8::Object>::Cast(val);
-  WrapperInfo* info = WrapperInfo::From(obj);
-
-  // If this fails, the object is not managed by Gin. It is either a normal JS
-  // object that's not wrapping any external C++ object, or it is wrapping some
-  // C++ object, but that object isn't managed by Gin (maybe Blink).
-  if (!info)
-    return NULL;
-
-  // If this fails, the object is managed by Gin, but it's not wrapping an
-  // instance of the C++ class associated with wrapper_info.
-  if (info != wrapper_info)
-    return NULL;
-
-  return obj->GetAlignedPointerFromInternalField(kEncodedValueIndex);
-}
-
-}  // namespace internal
-
 }  // namespace gin