servo: Merge #18404 - Measure PropertyDeclaration better (from nnethercote:measure-PropertyDeclaration); r=heycam

This increases the style-sheets counts for gmail by about 30 MiB.

<!-- Please describe your changes on the following line: -->

r? @heycam

---
<!-- Thank you for contributing to Servo! Please replace each `[ ]` by `[X]` when the step is complete, and replace `__` with appropriate data: -->
- [X] `./mach build -d` does not report any errors
- [X] `./mach test-tidy` does not report any errors
- [ ] These changes fix #__ (github issue number if applicable).

<!-- Either: -->
- [ ] There are tests for these changes OR
- [X] These changes do not require tests because code is tested on the Gecko side.

<!-- Also, please make sure that "Allow edits from maintainers" checkbox is checked, so that we can help you if you get stuck somewhere along the way.-->

<!-- Pull requests that do not address these steps are welcome, but they will require additional verification as part of the review process. -->

Source-Repo: https://github.com/servo/servo
Source-Revision: dfc38fabdcac0e027db3dc5425899004309fc68b

--HG--
extra : subtree_source : https%3A//hg.mozilla.org/projects/converted-servo-linear
extra : subtree_revision : 8a3535b25bb7e13f7f3f1ba9a70f23083ee204de

servo/components/style/properties/properties.mako.rs

@@ -38,7 +38,8 @@ use selectors::parser::SelectorParseError;
 use shared_lock::StylesheetGuards;
 use style_traits::{PARSING_MODE_DEFAULT, ToCss, ParseError};
 use style_traits::{PropertyDeclarationParseError, StyleParseError, ValueParseError};
-use stylesheets::{CssRuleType, MallocSizeOf, MallocSizeOfFn, Origin, UrlExtraData};
+use stylesheets::{CssRuleType, MallocSizeOf, MallocSizeOfBox, MallocSizeOfFn, MallocSizeOfVec};
+use stylesheets::{Origin, UrlExtraData};
 #[cfg(feature = "servo")] use values::Either;
 use values::generics::text::LineHeight;
 use values::computed;
@@ -1328,10 +1329,26 @@ impl ToCss for PropertyDeclaration {
 }
 
 impl MallocSizeOf for PropertyDeclaration {
-    fn malloc_size_of_children(&self, _malloc_size_of: MallocSizeOfFn) -> usize {
-        // The variants of PropertyDeclaration mostly (entirely?) contain
-        // scalars, so this is reasonable.
-        0
+    fn malloc_size_of_children(&self, malloc_size_of: MallocSizeOfFn) -> usize {
+        match *self {
+            % for property in data.longhands:
+                % if property.boxed and property.is_vector:
+                    <% raise Exception("this should not happen! not smart to box a vector here") %>
+                % elif property.boxed:
+                    PropertyDeclaration::${property.camel_case}(ref sv_box) => {
+                        sv_box.malloc_shallow_size_of_box(malloc_size_of)
+                    }
+                % elif property.is_vector:
+                    PropertyDeclaration::${property.camel_case}(ref sv_vec) => {
+                        sv_vec.0.malloc_shallow_size_of_vec(malloc_size_of)
+                    }
+                % endif
+            % endfor
+            PropertyDeclaration::CSSWideKeyword(..) => 0,
+            PropertyDeclaration::WithVariables(..) => 0,
+            PropertyDeclaration::Custom(..) => 0,
+            _ => 0,
+        }
     }
 }