Implement aura::PropertyConverter for mus interop.

ui/aura/mus/property_converter.cc

+// Copyright 2016 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 "ui/aura/mus/property_converter.h"
+
+#include "mojo/public/cpp/bindings/type_converter.h"
+#include "services/ui/public/cpp/property_type_converters.h"
+#include "services/ui/public/interfaces/window_manager.mojom.h"
+#include "ui/aura/client/aura_constants.h"
+#include "ui/aura/window_property.h"
+
+namespace aura {
+
+namespace {
+
+// Get the aura property key and name for a mus property transport |name|.
+bool GetPropertyKeyForTransportName(const std::string& name,
+                                    const void** key_out,
+                                    const char** name_out) {
+  if (name == ui::mojom::WindowManager::kAlwaysOnTop_Property) {
+    *key_out = client::kAlwaysOnTopKey;
+    *name_out = client::kAlwaysOnTopKey->name;
+    return true;
+  }
+  return false;
+}
+
+}  // namespace
+
+PropertyConverter::PropertyConverter() {}
+
+PropertyConverter::~PropertyConverter() {}
+
+bool PropertyConverter::ConvertPropertyForTransport(
+    Window* window,
+    const void* key,
+    std::string* server_property_name,
+    std::unique_ptr<std::vector<uint8_t>>* server_property_value) {
+  *server_property_name = GetTransportNameForPropertyKey(key);
+  if (!server_property_name->empty()) {
+    // TODO(msw): Using the int64_t accessor is wasteful for bool, etc.
+    const int64_t value = window->GetPropertyInternal(key, 0);
+    *server_property_value = base::MakeUnique<std::vector<uint8_t>>(
+        mojo::ConvertTo<std::vector<uint8_t>>(value));
+    return true;
+  }
+  DVLOG(2) << "Unknown aura property key: " << key;
+  return false;
+}
+
+std::string PropertyConverter::GetTransportNameForPropertyKey(const void* key) {
+  if (key == client::kAlwaysOnTopKey || key == client::kAlwaysOnTopKey->name)

[sky, 2016/11/11 22:59:15]

How do we end up using client::kAlwaysOnTopKey->name? By that I mean who passes
that property->key?

[msw, 2016/11/11 23:10:50]

Removed. Good catch, this just supported an earlier version of the patch.

+    return ui::mojom::WindowManager::kAlwaysOnTop_Property;
+  return std::string();
+}
+
+void PropertyConverter::SetPropertyFromTransportValue(
+    Window* window,
+    const std::string& server_property_name,
+    const std::vector<uint8_t>* data) {
+  const void* key = nullptr;
+  const char* name = nullptr;
+  if (GetPropertyKeyForTransportName(server_property_name, &key, &name)) {
+    DCHECK(key);
+    DCHECK(name);
+    // Aura window only supports property types that fit in int64_t.
+    CHECK_LE(8u, data->size()) << " Property type not supported: " << key;
+    const int64_t value = mojo::ConvertTo<int64_t>(*data);
+    // TODO(msw): Should aura::Window just store all properties by name?
+    window->SetPropertyInternal(key, name, nullptr, value, 0);
+  } else {
+    DVLOG(2) << "Unknown mus property name: " << server_property_name;
+  }
+}
+
+}  // namespace aura