Remove the concept of 'nonproperties' from ComputedStyle generator.

When we generate ComputedStyle, we differentiate between properties
(which are meant to correspond to CSS properties) and nonproperties
(everything else). However, this terminology is confusing:

- Some nonproperties are derived from real CSS properties (e.g.
  hasSimpleUnderline).
- The generator code contains a lot of "for property_ in nonproperties"
  which is quite confusing.
- The name does not reveal the actual difference between properties
  and nonproperties in terms of code generation.

This patch removes the field role of 'nonproperty' in favour of the
parameter 'has_custom_compare_and_copy'. So there are only two field
roles: 'property' (which includes flags like 'unique' and 'emptyState')
and 'inherited_flag'.

BUG=628043

Review-Url: https://codereview.chromium.org/2830983003
Cr-Commit-Position: refs/heads/master@{#468279}

third_party/WebKit/Source/build/scripts/make_computed_style_base.py

@@ -76,7 +76,6 @@ class Field(object):
             - 'property': for fields that store CSS properties
             - 'inherited_flag': for single-bit flags that store whether a property is
                                 inherited by this style or set explicitly
-            - 'nonproperty': for fields that are not CSS properties
         name_for_methods: String used to form the names of getters and setters.
             Should be in upper camel case.
         property_name: Name of the property that the field is part of.
@@ -89,7 +88,7 @@ class Field(object):
     """
 
     def __init__(self, field_role, name_for_methods, property_name, type_name,
-                 field_template, field_group, size, default_value,
+                 field_template, field_group, size, default_value, has_custom_compare_and_copy,
                  getter_method_name, setter_method_name, initial_method_name, **kwargs):
         """Creates a new field."""
         self.name = class_member_name(name_for_methods)
@@ -100,13 +99,13 @@ class Field(object):
         self.group_member_name = class_member_name(join_name(field_group, 'data')) if field_group else None
         self.size = size
         self.default_value = default_value
+        self.has_custom_compare_and_copy = has_custom_compare_and_copy
 
         # Field role: one of these must be true
         self.is_property = field_role == 'property'
         self.is_inherited_flag = field_role == 'inherited_flag'
-        self.is_nonproperty = field_role == 'nonproperty'
-        assert (self.is_property, self.is_inherited_flag, self.is_nonproperty).count(True) == 1, \
-            'Field role has to be exactly one of: property, inherited_flag, nonproperty'
+        assert (self.is_property, self.is_inherited_flag).count(True) == 1, \
+            'Field role has to be exactly one of: property, inherited_flag'
 
         if not self.is_inherited_flag:
             self.is_inherited = kwargs.pop('inherited')
@@ -177,12 +176,10 @@ def _create_enums(properties):
     return OrderedDict(sorted(enums.items(), key=lambda t: t[0]))
 
 
-def _create_field(field_role, property_):
+def _create_property_field(property_):
     """
-    Create a property or nonproperty field.
+    Create a property field.
     """
-    assert field_role in ('property', 'nonproperty')
-
     name_for_methods = property_['name_for_methods']
 
     assert property_['default_value'] is not None, \
@@ -213,7 +210,7 @@ def _create_field(field_role, property_):
         size = 1
 
     return Field(
-        field_role,
+        'property',
         name_for_methods,
         property_name=property_['name'],
         inherited=property_['inherited'],
@@ -223,6 +220,7 @@ def _create_field(field_role, property_):
         field_group=property_['field_group'],
         size=size,
         default_value=default_value,
+        has_custom_compare_and_copy=property_['has_custom_compare_and_copy'],
         getter_method_name=property_['getter'],
         setter_method_name=property_['setter'],
         initial_method_name=property_['initial'],
@@ -244,6 +242,7 @@ def _create_inherited_flag_field(property_):
         field_group=property_['field_group'],
         size=1,
         default_value='true',
+        has_custom_compare_and_copy=False,
         getter_method_name=method_name(name_for_methods),
         setter_method_name=method_name(join_name('set', name_for_methods)),
         initial_method_name=method_name(join_name('initial', name_for_methods)),
@@ -252,7 +251,7 @@ def _create_inherited_flag_field(property_):
 
 def _create_fields(properties):
     """
-    Create ComputedStyle fields from properties or nonproperties and return a list of Field objects.
+    Create ComputedStyle fields from properties and return a list of Field objects.
     """
     fields = []
     for property_ in properties:
@@ -263,11 +262,7 @@ def _create_fields(properties):
             if property_['independent']:
                 fields.append(_create_inherited_flag_field(property_))
 
-            # TODO(shend): Get rid of the property/nonproperty field roles.
-            # If the field has_custom_compare_and_copy, then it does not appear in
-            # ComputedStyle::operator== and ComputedStyle::CopyNonInheritedFromCached.
-            field_role = 'nonproperty' if property_['has_custom_compare_and_copy'] else 'property'
-            fields.append(_create_field(field_role, property_))
+            fields.append(_create_property_field(property_))
 
     return fields
 

third_party/WebKit/Source/build/scripts/templates/ComputedStyleBase.cpp.tmpl

@@ -25,6 +25,7 @@ ASSERT_SIZE(ComputedStyleBase, SameSizeAsComputedStyleBase);
 void ComputedStyleBase::InheritFrom(const ComputedStyleBase& other,
                                     IsAtShadowBoundary isAtShadowBoundary) {
   {{fieldwise_copy(computed_style, computed_style.all_fields
+      |selectattr("is_property")
       |selectattr("is_inherited")
       |list
     )|indent(2)}}
@@ -33,7 +34,7 @@ void ComputedStyleBase::InheritFrom(const ComputedStyleBase& other,
 void ComputedStyleBase::CopyNonInheritedFromCached(
     const ComputedStyleBase& other) {
   {{fieldwise_copy(computed_style, computed_style.all_fields
-      |rejectattr("is_nonproperty")
+      |rejectattr("has_custom_compare_and_copy")
       |rejectattr("is_inherited")
       |list
     )|indent(2)}}

third_party/WebKit/Source/build/scripts/templates/ComputedStyleBase.h.tmpl

@@ -39,6 +39,7 @@ class CORE_EXPORT ComputedStyleBase {
   inline bool IndependentInheritedEqual(const ComputedStyleBase& o) const {
     return (
         {{fieldwise_compare(computed_style, computed_style.all_fields
+            |selectattr("is_property")
             |selectattr("is_inherited")
             |selectattr("is_independent")
             |list
@@ -50,6 +51,7 @@ class CORE_EXPORT ComputedStyleBase {
   inline bool NonIndependentInheritedEqual(const ComputedStyleBase& o) const {
     return (
         {{fieldwise_compare(computed_style, computed_style.all_fields
+            |selectattr("is_property")
             |selectattr("is_inherited")
             |rejectattr("is_independent")
             |list
@@ -66,6 +68,7 @@ class CORE_EXPORT ComputedStyleBase {
     return (
         {{fieldwise_compare(computed_style, computed_style.all_fields
             |selectattr("is_property")
+            |rejectattr("has_custom_compare_and_copy")
             |rejectattr("is_inherited")
             |list
           )|indent(8)}}