Add PropertyConverter support for non-zero default primitive values.

ui/aura/mus/property_converter.h

 // 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.
 
 #ifndef UI_AURA_MUS_PROPERTY_CONVERTER_H_
 #define UI_AURA_MUS_PROPERTY_CONVERTER_H_
 
 #include <stdint.h>
 
 #include <map>
@@ skipping 52 matching lines @@
   // primitive.
   bool GetPropertyValueFromTransportValue(
       const std::string& transport_name,
       const std::vector<uint8_t>& transport_data,
       PrimitiveType* value);
 
   // Register a property to support conversion between mus and aura.
   template<typename T>
   void RegisterProperty(const WindowProperty<T>* property,
                         const char* transport_name) {
-    primitive_properties_[property] =
-        PropertyNames(property->name, transport_name);
+    PrimitiveProperty primitive_property;
+    primitive_property.property_name = property->name;
+    primitive_property.transport_name = transport_name;
+    primitive_property.default_value = property->default_value;
+    primitive_properties_[property] = primitive_property;
   }
 
   // Specializations for properties to pointer types supporting mojo conversion.
   void RegisterProperty(const WindowProperty<gfx::ImageSkia*>* property,
                         const char* transport_name);
   void RegisterProperty(const WindowProperty<gfx::Rect*>* property,
                         const char* transport_name);
   void RegisterProperty(const WindowProperty<gfx::Size*>* property,
                         const char* transport_name);
   void RegisterProperty(const WindowProperty<std::string*>* property,
                         const char* transport_name);
   void RegisterProperty(const WindowProperty<base::string16*>* property,
                         const char* transport_name);
 
  private:
-  // A pair with the aura::WindowProperty::name and the mus property name.
-  using PropertyNames = std::pair<const char*, const char*>;
-  // A map of aura::WindowProperty<T> to its aura and mus property names.
+  // Contains data needed to store and convert primitive-type properties.
+  struct PrimitiveProperty {
+    // The aura::WindowProperty::name used for storage.
+    const char* property_name = nullptr;
+    // The mus property name used for transport.
+    const char* transport_name = nullptr;
+    // The aura::WindowProperty::default_value stored using PrimitiveType.
+    PrimitiveType default_value = 0;
+  };
+
+  // A map of aura::WindowProperty<T> to PrimitiveProperty structs.
   // This supports the internal codepaths for primitive types, eg. T=bool.
-  std::map<const void*, PropertyNames> primitive_properties_;
+  std::map<const void*, PrimitiveProperty> primitive_properties_;
 
   // Maps of aura::WindowProperty<T> to their mus property names.
   // This supports types that can be serialized for Mojo, eg. T=std::string*.
   std::map<const WindowProperty<gfx::ImageSkia*>*, const char*>
       image_properties_;
   std::map<const WindowProperty<gfx::Rect*>*, const char*> rect_properties_;
   std::map<const WindowProperty<gfx::Size*>*, const char*> size_properties_;
   std::map<const WindowProperty<std::string*>*, const char*> string_properties_;
   std::map<const WindowProperty<base::string16*>*, const char*>
       string16_properties_;
 
   DISALLOW_COPY_AND_ASSIGN(PropertyConverter);
 };
 
 }  // namespace aura
 
 #endif  // UI_AURA_MUS_PROPERTY_CONVERTER_H_