Move body of PriorityCompare to SVGSMILElement

Move the priority comparison between two timed elements into the new
SVGSMILElement::IsHigherPriorityThan() method. This ought to make fixing
the existing FIXME easier.

Bug: 998526
Change-Id: I05492faa770cb9eaf8589e88cbf86845f870c9ec
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/1841131
Commit-Queue: Fredrik Söderquist <fs@opera.com>
Reviewed-by: Stephen Chenney <schenney@chromium.org>
Cr-Commit-Position: refs/heads/master@{#703081}

third_party/blink/renderer/core/svg/animation/smil_animation_sandwich.cc

@@ -37,13 +37,7 @@ struct PriorityCompare {
   PriorityCompare(SMILTime elapsed) : elapsed_(elapsed) {}
   bool operator()(const Member<SVGSMILElement>& a,
                   const Member<SVGSMILElement>& b) {
-    // FIXME: This should also consider possible timing relations between the
-    // elements.
-    SMILTime a_begin = a->BeginTimeForPrioritization(elapsed_);
-    SMILTime b_begin = b->BeginTimeForPrioritization(elapsed_);
-    if (a_begin == b_begin)
-      return a->DocumentOrderIndex() < b->DocumentOrderIndex();
-    return a_begin < b_begin;
+    return b->IsHigherPriorityThan(a, elapsed_);
   }
   SMILTime elapsed_;
 };

third_party/blink/renderer/core/svg/animation/svg_smil_element.cc

@@ -605,6 +605,17 @@ SMILTime SVGSMILElement::BeginTimeForPrioritization(
   return interval_.begin;
 }
 
+bool SVGSMILElement::IsHigherPriorityThan(const SVGSMILElement* other,
+                                          SMILTime presentation_time) const {
+  // FIXME: This should also consider possible timing relations between the
+  // elements.
+  SMILTime this_begin = BeginTimeForPrioritization(presentation_time);
+  SMILTime other_begin = other->BeginTimeForPrioritization(presentation_time);
+  if (this_begin == other_begin)
+    return DocumentOrderIndex() > other->DocumentOrderIndex();
+  return this_begin > other_begin;
+}
+
 SMILTime SVGSMILElement::Dur() const {
   if (cached_dur_ != kInvalidCachedTime)
     return cached_dur_;

third_party/blink/renderer/core/svg/animation/svg_smil_element.h

@@ -82,12 +82,13 @@ class CORE_EXPORT SVGSMILElement : public SVGElement, public SVGTests {
   SMILTime Elapsed() const;
 
   SMILTime IntervalBegin() const { return interval_.begin; }
-  SMILTime BeginTimeForPrioritization(SMILTime presentation_time) const;
   SMILTime SimpleDuration() const;
 
   bool CurrentIntervalIsActive(SMILTime elapsed);
   void UpdateInterval(SMILTime presentation_time);
   void UpdateActiveState(SMILTime elapsed);
+  bool IsHigherPriorityThan(const SVGSMILElement* other,
+                            SMILTime presentation_time) const;
 
   SMILTime NextInterestingTime(SMILTime elapsed) const;
   SMILTime NextProgressTime(SMILTime elapsed) const;
@@ -157,6 +158,7 @@ class CORE_EXPORT SVGSMILElement : public SVGElement, public SVGTests {
   SMILTime FindInstanceTime(BeginOrEnd,
                             SMILTime minimum_time,
                             bool equals_minimum_ok) const;
+  SMILTime BeginTimeForPrioritization(SMILTime presentation_time) const;
 
   SMILInterval ResolveInterval(SMILTime begin_after, SMILTime end_after) const;
   bool ResolveFirstInterval();