Take and return primitive types by value in ComputedStyle.

third_party/WebKit/Source/build/scripts/templates/fields/field.tmpl

Index: third_party/WebKit/Source/build/scripts/templates/fields/field.tmpl
diff --git a/third_party/WebKit/Source/build/scripts/templates/fields/field.tmpl b/third_party/WebKit/Source/build/scripts/templates/fields/field.tmpl
index f09fc2b5068ceb312eab707f67a312ea849c6d08..07b493cda245ea2a0aae6734f7882d93568b4e4f 100644
--- a/third_party/WebKit/Source/build/scripts/templates/fields/field.tmpl
+++ b/third_party/WebKit/Source/build/scripts/templates/fields/field.tmpl
@@ -40,7 +40,7 @@ if (!({{getter_expression(field)}} == {{value}}))
 {% endmacro %}
 
 {% macro nonconst_ref(field) %}
-{% if field.is_bit_field -%}
+{% if field.is_bit_field or field.field_template == 'primitive' -%}
 {{field.type_name}}
 {%- else -%}
 {{field.type_name}}&
@@ -48,7 +48,7 @@ if (!({{getter_expression(field)}} == {{value}}))
 {% endmacro %}
 
 {% macro const_ref(field) %}
-{% if field.is_bit_field -%}
+{% if field.is_bit_field or field.field_template == 'primitive' -%}
 {{field.type_name}}
 {%- else -%}
 const {{field.type_name}}&
@@ -123,4 +123,4 @@ if ({{group.group_name}}.Get() != other.{{group.group_name}}.Get()) {
 if (self.{{expression}} != other.{{expression}})
   return true;
 {% endfor %}
-{% endmacro %}
+{% endmacro %}