Bug 1834133 part 1: Remove about:config prefs layout.css.notify-of-unvisited and layout.css.always-repaint-on-unvisited. r=emilio

Update all of their usages to assume that they're true (which they have been, by-default, for several years).

Differential Revision: https://phabricator.services.mozilla.com/D178569

docshell/base/BaseHistory.cpp

@@ -116,9 +116,6 @@ void BaseHistory::RegisterVisitedCallback(nsIURI* aURI, Link* aLink) {
     case VisitedStatus::Unknown:
       break;
     case VisitedStatus::Unvisited:
-      if (!StaticPrefs::layout_css_notify_of_unvisited()) {
-        break;
-      }
       [[fallthrough]];
     case VisitedStatus::Visited:
       aLink->VisitedQueryFinished(links->mStatus == VisitedStatus::Visited);
@@ -159,11 +156,6 @@ void BaseHistory::NotifyVisited(
   MOZ_ASSERT(NS_IsMainThread());
   MOZ_ASSERT(aStatus != VisitedStatus::Unknown);
 
-  if (aStatus == VisitedStatus::Unvisited &&
-      !StaticPrefs::layout_css_notify_of_unvisited()) {
-    return;
-  }
-
   NotifyVisitedInThisProcess(aURI, aStatus);
   if (XRE_IsParentProcess()) {
     NotifyVisitedFromParent(aURI, aStatus, aListOfProcessesToNotify);

dom/base/Link.cpp

@@ -81,12 +81,10 @@ void Link::VisitedQueryFinished(bool aVisited) {
   // Tell the element to update its visited state.
   mElement->UpdateState(true);
 
-  if (StaticPrefs::layout_css_always_repaint_on_unvisited()) {
-    // Even if the state didn't actually change, we need to repaint in order for
-    // the visited state not to be observable.
-    nsLayoutUtils::PostRestyleEvent(GetElement(), RestyleHint::RestyleSubtree(),
-                                    nsChangeHint_RepaintFrame);
-  }
+  // Even if the state didn't actually change, we need to repaint in order for
+  // the visited state not to be observable.
+  nsLayoutUtils::PostRestyleEvent(GetElement(), RestyleHint::RestyleSubtree(),
+                                  nsChangeHint_RepaintFrame);
 }
 
 ElementState Link::LinkState() const {

layout/base/RestyleManager.cpp

@@ -3300,24 +3300,17 @@ void RestyleManager::ElementStateChanged(Element* aElement,
   const ElementState kVisitedAndUnvisited =
       ElementState::VISITED | ElementState::UNVISITED;
 
-  // When visited links are disabled, they cannot influence style for obvious
-  // reasons.
-  //
-  // When layout.css.always-repaint-on-unvisited is true, we'll restyle when the
-  // relevant visited query finishes, regardless of the style (see
-  // Link::VisitedQueryFinished). So there's no need to do anything as a result
-  // of this state change just yet.
+  // We'll restyle when the relevant visited query finishes, regardless of the
+  // style (see Link::VisitedQueryFinished). So there's no need to do anything
+  // as a result of this state change just yet.
   //
   // Note that this check checks for _both_ bits: This is only true when visited
   // changes to unvisited or vice-versa, but not when we start or stop being a
   // link itself.
   if (aChangedBits.HasAllStates(kVisitedAndUnvisited)) {
-    if (!Gecko_VisitedStylesEnabled(aElement->OwnerDoc()) ||
-        StaticPrefs::layout_css_always_repaint_on_unvisited()) {
-      aChangedBits &= ~kVisitedAndUnvisited;
-      if (aChangedBits.IsEmpty()) {
-        return;
-      }
+    aChangedBits &= ~kVisitedAndUnvisited;
+    if (aChangedBits.IsEmpty()) {
+      return;
     }
   }
 

modules/libpref/init/StaticPrefList.yaml

@@ -8287,18 +8287,6 @@
   value: true
   mirror: always
 
-# Whether we get notified of history queries for visited even if unvisited.
-- name: layout.css.notify-of-unvisited
-  type: RelaxedAtomicBool
-  value: true
-  mirror: always
-
-# Whether we always restyle / repaint as a result of a visited query
-- name: layout.css.always-repaint-on-unvisited
-  type: RelaxedAtomicBool
-  value: true
-  mirror: always
-
 # Make `zoom` a `transform` + `transform-origin` alias.
 - name: layout.css.zoom-transform-hack.enabled
   type: RelaxedAtomicBool

toolkit/components/places/tests/gtest/mock_Link.h

@@ -43,9 +43,7 @@ class mock_Link : public mozilla::dom::Link {
   bool GotNotified() const { return !mDeathGrip; }
 
   void AwaitNewNotification(Handler aNewHandler) {
-    MOZ_ASSERT(
-        !mDeathGrip || !mozilla::StaticPrefs::layout_css_notify_of_unvisited(),
-        "Still waiting for a notification");
+    MOZ_ASSERT(!mDeathGrip, "Still waiting for a notification");
     // Create a cyclic ownership, so that the link will be released only
     // after its status has been updated.  This will ensure that, when it should
     // run the next test, it will happen at the end of the test function, if

toolkit/components/places/tests/gtest/test_IHistory.cpp

@@ -165,10 +165,8 @@ void test_visited_notifies() {
 void test_unvisited_does_not_notify_part2() {
   using namespace test_unvisited_does_not_notify;
 
-  if (StaticPrefs::layout_css_notify_of_unvisited()) {
-    SpinEventLoopUntil("places:test_unvisited_does_not_notify_part2"_ns,
-                       [&]() { return testLink->GotNotified(); });
-  }
+  SpinEventLoopUntil("places:test_unvisited_does_not_notify_part2"_ns,
+                     [&]() { return testLink->GotNotified(); });
 
   // We would have had a failure at this point had the content node been told it
   // was visited. Therefore, now we change it so that it expects a visited
@@ -238,10 +236,8 @@ void test_new_visit_notifies_waiting_Link() {
   nsCOMPtr<IHistory> history = do_get_IHistory();
   history->RegisterVisitedCallback(testURI, link);
 
-  if (StaticPrefs::layout_css_notify_of_unvisited()) {
-    SpinEventLoopUntil("places:test_new_visit_notifies_waiting_Link"_ns,
-                       [&]() { return link->GotNotified(); });
-  }
+  SpinEventLoopUntil("places:test_new_visit_notifies_waiting_Link"_ns,
+                     [&]() { return link->GotNotified(); });
 
   link->AwaitNewNotification(expect_visit);