Add macro to diff the groups (and their members) in ComputedStyleBase

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

 {% from 'macros.tmpl' import license %}
-{% from 'fields/field.tmpl' import getter_expression, setter_expression, fieldwise_copy %}
+{% from 'fields/field.tmpl' import getter_expression, setter_expression, fieldwise_copy, fieldwise_diff %}
 {{license()}}
 
 #include "core/ComputedStyleBase.h"
 #include "platform/wtf/SizeAssertions.h"
 
 namespace blink {
 
 struct SameSizeAsComputedStyleBase {
   {% if computed_style.subgroups is defined %}
   void* dataRefs[{{computed_style.subgroups|length}}];
@@ skipping 28 matching lines @@
 }
 
 void ComputedStyleBase::PropagateIndependentInheritedProperties(
     const ComputedStyleBase& parentStyle) {
   {% for field in computed_style.all_fields if field.is_property and field.is_independent %}
   if ({{field.is_inherited_method_name}}())
     {{setter_expression(field)}} = parentStyle.{{getter_expression(field)}};
   {% endfor %}
 }
 
+bool ComputedStyleBase::ScrollAnchorDisablingPropertyChanged(
+    const ComputedStyleBase& other,
+    const StyleDifference& diff) const {
+  {{fieldwise_diff(computed_style, computed_style.all_fields
+      |selectattr("property_name", "in", ["bottom", "left", "margin-bottom", "margin-left", "margin-right", "margin-top", "padding-bottom", "padding-left", "padding-right", "padding-top", "right", "top"])

[shend, 2017/05/03 05:18:12]

I would order these properties in their original order, in case perf is
sensitive to the order.

[nainar, 2017/05/03 06:49:57]

Done.

+      |list
+    )|indent(2)}}
+  return false;
+}
+
+bool ComputedStyleBase::DiffNeedsFullLayoutAndPaintInvalidation(
+    const ComputedStyleBase& other) const {
+  {{fieldwise_diff(computed_style, computed_style.all_fields
+      |selectattr("property_name", "in", ["padding-bottom", "padding-left", "padding-right", "padding-top"])

[shend, 2017/05/03 05:18:12]

same here.

[nainar, 2017/05/03 06:49:57]

Done.

+      |list
+    )|indent(2)}}
+  return false;
+}
+
 } // namespace blink