Avoid redundant hash calculations in CustomElementUpgradeSorter
Pointed out by tkent in https://codereview.chromium.org/2242743002/
The original code could do 2 hash calculations for
adding a new key-value pair to ParentChildMap
(for find() and add()), and rehashing the map
may involve copying the HeapHashSet<Member<Node>>
objects.
Change the value part of ParentChildMap from a HeapHashMap
object to its pointer, to avoid redundant hash calculation
and object copy.
This does not change any functionality of the class.
BUG=594918
Review-Url: https://codereview.chromium.org/2290543002
Cr-Commit-Position: refs/heads/master@{#415251}
2 files changed
