Merge the tonic layer from skydart branch back to master

sky/engine/tonic/dart_wrappable.cc

Index: sky/engine/tonic/dart_wrappable.cc
diff --git a/sky/engine/tonic/dart_wrappable.cc b/sky/engine/tonic/dart_wrappable.cc
new file mode 100644
index 0000000000000000000000000000000000000000..6c7e3a15267fff3b4a7c22cbbdb5dafe79cffc24
--- /dev/null
+++ b/sky/engine/tonic/dart_wrappable.cc
@@ -0,0 +1,91 @@
+// Copyright 2015 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 "sky/engine/config.h"
+#include "sky/engine/tonic/dart_wrappable.h"
+
+#include "sky/engine/tonic/dart_class_library.h"
+#include "sky/engine/tonic/dart_error.h"
+#include "sky/engine/tonic/dart_state.h"
+#include "sky/engine/tonic/dart_wrapper_info.h"
+
+namespace blink {
+
+DartWrappable::~DartWrappable() {
+  CHECK(!dart_wrapper_);
+}
+
+void DartWrappable::AcceptDartGCVisitor(DartGCVisitor& visitor) const {
+}
+
+Dart_Handle DartWrappable::CreateDartWrapper(DartState* dart_state) {
+  DCHECK(!dart_wrapper_);
+  const DartWrapperInfo& info = GetDartWrapperInfo();
+
+  Dart_PersistentHandle type = dart_state->class_library().GetClass(info);
+  DCHECK(!LogIfError(type));
+
+  intptr_t native_fields[kNumberOfNativeFields];
+  native_fields[kPeerIndex] = reinterpret_cast<intptr_t>(this);
+  native_fields[kWrapperInfoIndex] = reinterpret_cast<intptr_t>(&info);
+  Dart_Handle wrapper =
+      Dart_AllocateWithNativeFields(type, kNumberOfNativeFields, native_fields);
+  DCHECK(!LogIfError(wrapper));
+
+  info.ref_object(this);  // Balanced in FinalizeDartWrapper.
+  dart_wrapper_ = Dart_NewPrologueWeakPersistentHandle(
+      wrapper, this, info.size_in_bytes, &FinalizeDartWrapper);
+
+  return wrapper;
+}
+
+void DartWrappable::FinalizeDartWrapper(void* isolate_callback_data,
+                                        Dart_WeakPersistentHandle wrapper,
+                                        void* peer) {
+  DartWrappable* wrappable = reinterpret_cast<DartWrappable*>(peer);
+  wrappable->dart_wrapper_ = nullptr;
+  const DartWrapperInfo& info = wrappable->GetDartWrapperInfo();
+  info.deref_object(wrappable);  // Balanced in CreateDartWrapper.
+}
+
+DartWrappable* DartConverterWrappable::FromDart(Dart_Handle handle) {
+  intptr_t* peer = 0;
+  Dart_Handle result =
+      Dart_GetNativeInstanceField(handle, DartWrappable::kPeerIndex, peer);
+  if (Dart_IsError(result))
+    return nullptr;
+  return reinterpret_cast<DartWrappable*>(peer);
+}
+
+DartWrappable* DartConverterWrappable::FromArguments(Dart_NativeArguments args,
+                                                     int index,
+                                                     Dart_Handle& exception) {
+  intptr_t native_fields[DartWrappable::kNumberOfNativeFields];
+  Dart_Handle result = Dart_GetNativeFieldsOfArgument(
+      args, index, DartWrappable::kNumberOfNativeFields, native_fields);
+  if (Dart_IsError(result)) {
+    exception = Dart_NewStringFromCString(DartError::kInvalidArgument);
+    return nullptr;
+  }
+  return reinterpret_cast<DartWrappable*>(
+      native_fields[DartWrappable::kPeerIndex]);
+}
+
+DartWrappable* DartConverterWrappable::FromArgumentsWithNullCheck(
+    Dart_NativeArguments args, int index, Dart_Handle& exception) {
+    Dart_Handle handle = Dart_GetNativeArgument(args, index);
+  if (Dart_IsNull(handle))
+    return nullptr;
+  intptr_t native_fields[DartWrappable::kNumberOfNativeFields];
+  Dart_Handle result = Dart_GetNativeFieldsOfArgument(
+      args, index, DartWrappable::kNumberOfNativeFields, native_fields);
+  if (Dart_IsError(result)) {
+    exception = Dart_NewStringFromCString(DartError::kInvalidArgument);
+    return nullptr;
+  }
+  return reinterpret_cast<DartWrappable*>(
+      native_fields[DartWrappable::kPeerIndex]);
+}
+
+}  // namespace blink