From 015a249afc392d7f14f7ba5a517afafd0120d858 Mon Sep 17 00:00:00 2001
From: Hiroyuki Ikezoe <hikezoe@mozilla.com>
Date: Fri, 11 Aug 2017 12:55:32 -0700
Subject: [PATCH] Cleanup code that was used for verifying styling results for
 throttled animation flush in post traversal.

Now that we do process normal traversal even in the case of throttled animation
flush so that we don't need to do special handling for the case.

Note about the comment in has_current_styles():
the remaining animation hints is not caused by either this patch or the
previous patch in this patch series, it's been there in the first place, but
it should be fixed somehow later. See bug 1389675.

MozReview-Commit-ID: JojHufxNCiS
---
 components/style/dom.rs | 22 ++++++++++++++++++++++
 ports/geckolib/glue.rs  | 30 +++---------------------------
 2 files changed, 25 insertions(+), 27 deletions(-)

diff --git a/components/style/dom.rs b/components/style/dom.rs
index d2ed5ae3d99e..7df9c850fd42 100644
--- a/components/style/dom.rs
+++ b/components/style/dom.rs
@@ -462,6 +462,28 @@ pub trait TElement : Eq + PartialEq + Debug + Hash + Sized + Copy + Clone +
         data.has_styles() && !data.restyle.hint.has_non_animation_invalidations()
     }
 
+    /// Returns whether the element's styles are up-to-date after traversal
+    /// (i.e. in post traversal).
+    fn has_current_styles(&self, data: &ElementData) -> bool {
+        if self.has_snapshot() && !self.handled_snapshot() {
+            return false;
+        }
+
+        data.has_styles() &&
+        // TODO(hiro): When an animating element moved into subtree of
+        // contenteditable element, there remains animation restyle hints in
+        // post traversal. It's generally harmless since the hints will be
+        // processed in a next styling but ideally it should be processed soon.
+        //
+        // Without this, we get failures in:
+        //   layout/style/crashtests/1383319.html
+        //   layout/style/crashtests/1383001.html
+        //
+        // https://bugzilla.mozilla.org/show_bug.cgi?id=1389675 tracks fixing
+        // this.
+        !data.restyle.hint.has_non_animation_invalidations()
+    }
+
     /// Flag that this element has a descendant for style processing.
     ///
     /// Only safe to call with exclusive access to the element.
diff --git a/ports/geckolib/glue.rs b/ports/geckolib/glue.rs
index fddc9676ca5c..d20fce6fb139 100644
--- a/ports/geckolib/glue.rs
+++ b/ports/geckolib/glue.rs
@@ -2775,10 +2775,8 @@ pub extern "C" fn Servo_NoteExplicitHints(element: RawGeckoElementBorrowed,
 
 #[no_mangle]
 pub extern "C" fn Servo_TakeChangeHint(element: RawGeckoElementBorrowed,
-                                       raw_flags: ServoTraversalFlags,
                                        was_restyled: *mut bool) -> nsChangeHint
 {
-    let flags = TraversalFlags::from_bits_truncate(raw_flags);
     let mut was_restyled =  unsafe { was_restyled.as_mut().unwrap() };
     let element = GeckoElement(element);
 
@@ -2787,25 +2785,7 @@ pub extern "C" fn Servo_TakeChangeHint(element: RawGeckoElementBorrowed,
             *was_restyled = data.restyle.is_restyle();
 
             let damage = data.restyle.damage;
-            if flags.for_animation_only() {
-                if !*was_restyled {
-                    // Don't touch elements if the element was not restyled
-                    // in throttled animation flush.
-                    debug!("Skip post traversal for throttled animation flush {:?} restyle={:?}",
-                           element, data.restyle);
-                    return nsChangeHint(0);
-                }
-                // In the case where we call this function for post traversal for
-                // flusing throttled animations (i.e. without normal restyle
-                // traversal), we need to preserve restyle hints for normal restyle
-                // traversal. Restyle hints for animations have been already
-                // removed during animation-only traversal.
-                debug_assert!(!data.restyle.hint.has_animation_hint(),
-                              "Animation restyle hints should have been already removed");
-                data.clear_restyle_flags_and_damage();
-            } else {
-                data.clear_restyle_state();
-            }
+            data.clear_restyle_state();
             damage
         }
         None => {
@@ -2821,11 +2801,9 @@ pub extern "C" fn Servo_TakeChangeHint(element: RawGeckoElementBorrowed,
 
 #[no_mangle]
 pub extern "C" fn Servo_ResolveStyle(element: RawGeckoElementBorrowed,
-                                     _raw_data: RawServoStyleSetBorrowed,
-                                     raw_flags: ServoTraversalFlags)
+                                     _raw_data: RawServoStyleSetBorrowed)
                                      -> ServoStyleContextStrong
 {
-    let flags = TraversalFlags::from_bits_truncate(raw_flags);
     let element = GeckoElement(element);
     debug!("Servo_ResolveStyle: {:?}", element);
     let data =
@@ -2833,9 +2811,7 @@ pub extern "C" fn Servo_ResolveStyle(element: RawGeckoElementBorrowed,
 
     // TODO(emilio): Downgrade to debug assertions when close to release.
     assert!(data.has_styles(), "Resolving style on unstyled element");
-    // In the case where we process for throttled animation, there remaings
-    // restyle hints other than animation hints.
-    debug_assert!(element.has_current_styles_for_traversal(&*data, flags),
+    debug_assert!(element.has_current_styles(&*data),
                   "Resolving style on {:?} without current styles: {:?}", element, data);
     data.styles.primary().clone().into()
 }