stylo: Measure Elements and ComputedValues.

The patch provides FFI access to Gecko's SeenPtrs type from Rust, in
order to record what has already been measured when measuring Arcs. (The
SeenPtrs must be initialized on the Gecko side because the same table is
reused for measuring all Elements within a window, because Elements can
share ComputedValues.) I have confirmed with DMD that this is working
correctly.

The patch also introduces MallocSizeOfRepeats, which is like
MallocSizeOf but takes a SizeOfState, which holds a SeenPtrs table.

1 files changed, 15 insertions, 0 deletions

diff --git a/components/style/gecko/generated/structs_debug.rs b/components/style/gecko/generated/structs_debug.rs
index ac9ad2686ce..7d6eed0e140 100644
--- a/components/style/gecko/generated/structs_debug.rs
+++ b/components/style/gecko/generated/structs_debug.rs
@@ -6024,6 +6024,21 @@ pub mod root {
             MAX = 29,
         }
         #[repr(C)]
+        #[derive(Debug, Copy)]
+        pub struct SeenPtrs {
+            pub _bindgen_opaque_blob: [u64; 6usize],
+        }
+        #[test]
+        fn bindgen_test_layout_SeenPtrs() {
+            assert_eq!(::std::mem::size_of::<SeenPtrs>() , 48usize , concat !
+                       ( "Size of: " , stringify ! ( SeenPtrs ) ));
+            assert_eq! (::std::mem::align_of::<SeenPtrs>() , 8usize , concat !
+                        ( "Alignment of " , stringify ! ( SeenPtrs ) ));
+        }
+        impl Clone for SeenPtrs {
+            fn clone(&self) -> Self { *self }
+        }
+        #[repr(C)]
         #[derive(Debug)]
         pub struct URLExtraData {
             pub mRefCnt: root::mozilla::ThreadSafeAutoRefCnt,