Bug 1604689 - Fix 'identfiers' typos. r=asuth

Differential Revision: https://phabricator.services.mozilla.com/D57595 [wrupdater] From https://hg.mozilla.org/mozilla-central/rev/03449d72cc542f9f3ee65920e01ce64da4103c63
servo · bors-servo · Dec 20, 2019 · Dec 18, 2019 · Dec 18, 2019 · Dec 19, 2019
commit 3d7220a0f1da7f3bc36f78e440757257dad4998a
diff --git a/webrender/src/picture.rs b/webrender/src/picture.rs
@@ -431,7 +431,7 @@ impl PrimitiveDependencyInfo {
 }
 
 /// A stable ID for a given tile, to help debugging. These are also used
-/// as unique identfiers for tile surfaces when using a native compositor.
+/// as unique identifiers for tile surfaces when using a native compositor.
 #[derive(Debug, Copy, Clone, PartialEq)]
 #[cfg_attr(feature = "capture", derive(Serialize))]
 #[cfg_attr(feature = "replay", derive(Deserialize))]