Merging upstream version 125.0.1.

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>
author: Daniel Baumann <daniel.baumann@progress-linux.org> 2024-04-19 01:14:29 +0000
committer: Daniel Baumann <daniel.baumann@progress-linux.org> 2024-04-19 01:14:29 +0000
commit: fbaf0bb26397aa498eb9156f06d5a6fe34dd7dd8 (patch)
tree: 4c1ccaf5486d4f2009f9a338a98a83e886e29c97 /layout/style
parent: Releasing progress-linux version 124.0.1-1~progress7.99u1. (diff)
download: firefox-fbaf0bb26397aa498eb9156f06d5a6fe34dd7dd8.tar.xz
firefox-fbaf0bb26397aa498eb9156f06d5a6fe34dd7dd8.zip
40 files changed, 576 insertions, 477 deletions
diff --git a/layout/style/FontFaceSet.cpp b/layout/style/FontFaceSet.cpp
index f350e5210a..ddc6240216 100644
--- a/layout/style/FontFaceSet.cpp
+++ b/layout/style/FontFaceSet.cpp
@@ -439,7 +439,6 @@ void FontFaceSet::MaybeResolve() {
           break;
         case FontFaceLoadStatus::Loading:
           // We should've returned above at MightHavePendingFontLoads()!
-        case FontFaceLoadStatus::EndGuard_:
           MOZ_ASSERT_UNREACHABLE("unexpected FontFaceLoadStatus");
           break;
       }
diff --git a/layout/style/GeckoBindings.cpp b/layout/style/GeckoBindings.cpp
index 5c7992f8db..dc43e9cf6a 100644
--- a/layout/style/GeckoBindings.cpp
+++ b/layout/style/GeckoBindings.cpp
@@ -27,7 +27,6 @@
 #include "mozilla/dom/DocumentInlines.h"
 #include "nsILoadContext.h"
 #include "nsIFrame.h"
-#include "nsIMozBrowserFrame.h"
 #include "nsINode.h"
 #include "nsIURI.h"
 #include "nsFontMetrics.h"
@@ -44,6 +43,7 @@
 #include "mozilla/css/ImageLoader.h"
 #include "mozilla/DeclarationBlock.h"
 #include "mozilla/AttributeStyles.h"
+#include "mozilla/ClearOnShutdown.h"
 #include "mozilla/EffectCompositor.h"
 #include "mozilla/EffectSet.h"
 #include "mozilla/FontPropertyTypes.h"
diff --git a/layout/style/Loader.cpp b/layout/style/Loader.cpp
index ebbc934466..1ea37b094f 100644
--- a/layout/style/Loader.cpp
+++ b/layout/style/Loader.cpp
@@ -8,7 +8,9 @@
 
 #include "mozilla/css/Loader.h"
 
+#include "MainThreadUtils.h"
 #include "mozilla/ArrayUtils.h"
+#include "mozilla/css/ErrorReporter.h"
 #include "mozilla/dom/DocGroup.h"
 #include "mozilla/dom/FetchPriority.h"
 #include "mozilla/dom/SRILogHelper.h"
@@ -22,6 +24,7 @@
 #include "mozilla/SchedulerGroup.h"
 #include "mozilla/URLPreloader.h"
 #include "nsIChildChannel.h"
+#include "nsIPrincipal.h"
 #include "nsISupportsPriority.h"
 #include "nsITimedChannel.h"
 #include "nsICachingChannel.h"
@@ -34,7 +37,6 @@
 #include "nsICookieJarSettings.h"
 #include "mozilla/dom/Document.h"
 #include "nsIURI.h"
-#include "nsNetUtil.h"
 #include "nsContentUtils.h"
 #include "nsIScriptSecurityManager.h"
 #include "nsContentPolicyUtils.h"
@@ -64,6 +66,7 @@
 #include "mozilla/css/StreamLoader.h"
 #include "mozilla/SharedStyleSheetCache.h"
 #include "mozilla/StaticPrefs_layout.h"
+#include "mozilla/StaticPrefs_network.h"
 #include "mozilla/StaticPrefs_dom.h"
 #include "mozilla/StaticPrefs_network.h"
 #include "mozilla/Try.h"
@@ -308,7 +311,10 @@ SheetLoadData::SheetLoadData(
       mNonce(aNonce),
       mFetchPriority{aFetchPriority},
       mGuessedEncoding(GetFallbackEncoding(*aLoader, aOwningNode, nullptr)),
-      mCompatMode(aLoader->CompatMode(aPreloadKind)) {
+      mCompatMode(aLoader->CompatMode(aPreloadKind)),
+      mRecordErrors(
+          aLoader && aLoader->GetDocument() &&
+          css::ErrorReporter::ShouldReportErrors(*aLoader->GetDocument())) {
   MOZ_ASSERT(!aOwningNode || dom::LinkStyle::FromNode(*aOwningNode),
              "Must implement LinkStyle");
   MOZ_ASSERT(mTriggeringPrincipal);
@@ -349,7 +355,10 @@ SheetLoadData::SheetLoadData(css::Loader* aLoader, nsIURI* aURI,
       mFetchPriority(FetchPriority::Auto),
       mGuessedEncoding(GetFallbackEncoding(
           *aLoader, nullptr, aParentData ? aParentData->mEncoding : nullptr)),
-      mCompatMode(aLoader->CompatMode(mPreloadKind)) {
+      mCompatMode(aLoader->CompatMode(mPreloadKind)),
+      mRecordErrors(
+          aLoader && aLoader->GetDocument() &&
+          css::ErrorReporter::ShouldReportErrors(*aLoader->GetDocument())) {
   MOZ_ASSERT(mLoader, "Must have a loader!");
   MOZ_ASSERT(mTriggeringPrincipal);
   MOZ_ASSERT(!mUseSystemPrincipal || mSyncLoad,
@@ -391,7 +400,10 @@ SheetLoadData::SheetLoadData(
       mFetchPriority(aFetchPriority),
       mGuessedEncoding(
           GetFallbackEncoding(*aLoader, nullptr, aPreloadEncoding)),
-      mCompatMode(aLoader->CompatMode(aPreloadKind)) {
+      mCompatMode(aLoader->CompatMode(aPreloadKind)),
+      mRecordErrors(
+          aLoader && aLoader->GetDocument() &&
+          css::ErrorReporter::ShouldReportErrors(*aLoader->GetDocument())) {
   MOZ_ASSERT(mTriggeringPrincipal);
   MOZ_ASSERT(mLoader, "Must have a loader!");
   MOZ_ASSERT(!mUseSystemPrincipal || mSyncLoad,
@@ -639,43 +651,54 @@ static bool AllLoadsCanceled(const SheetLoadData& aData) {
  * page and check the mimetype on the channel to make sure we're not
  * loading non-text/css data in standards mode.
  */
-nsresult SheetLoadData::VerifySheetReadyToParse(nsresult aStatus,
-                                                const nsACString& aBytes1,
-                                                const nsACString& aBytes2,
-                                                nsIChannel* aChannel) {
+nsresult SheetLoadData::VerifySheetReadyToParse(
+    nsresult aStatus, const nsACString& aBytes1, const nsACString& aBytes2,
+    nsIChannel* aChannel, nsIURI* aFinalChannelURI,
+    nsIPrincipal* aChannelResultPrincipal) {
   LOG(("SheetLoadData::VerifySheetReadyToParse"));
-  NS_ASSERTION(!mLoader->mSyncCallback, "Synchronous callback from necko");
+  NS_ASSERTION((!NS_IsMainThread() || !mLoader->mSyncCallback),
+               "Synchronous callback from necko");
 
   if (AllLoadsCanceled(*this)) {
-    LOG_WARN(("  All loads are canceled, dropping"));
-    mLoader->SheetComplete(*this, NS_BINDING_ABORTED);
+    if (NS_IsMainThread()) {
+      LOG_WARN(("  All loads are canceled, dropping"));
+      mLoader->SheetComplete(*this, NS_BINDING_ABORTED);
+    }
+    return NS_OK;
+  }
+
+  if (!NS_IsMainThread() && mRecordErrors) {
+    // we cannot parse sheet OMT if we need to record errors
     return NS_OK;
   }
 
   if (NS_FAILED(aStatus)) {
-    LOG_WARN(
-        ("  Load failed: status 0x%" PRIx32, static_cast<uint32_t>(aStatus)));
-    // Handle sheet not loading error because source was a tracking URL (or
-    // fingerprinting, cryptomining, etc).
-    // We make a note of this sheet node by including it in a dedicated
-    // array of blocked tracking nodes under its parent document.
-    //
-    // Multiple sheet load instances might be tied to this request,
-    // we annotate each one linked to a valid owning element (node).
-    if (net::UrlClassifierFeatureFactory::IsClassifierBlockingErrorCode(
-            aStatus)) {
-      if (Document* doc = mLoader->GetDocument()) {
-        for (SheetLoadData* data = this; data; data = data->mNext) {
-          // owner node may be null but AddBlockTrackingNode can cope
-          doc->AddBlockedNodeByClassifier(data->mSheet->GetOwnerNode());
+    if (NS_IsMainThread()) {
+      LOG_WARN(
+          ("  Load failed: status 0x%" PRIx32, static_cast<uint32_t>(aStatus)));
+      // Handle sheet not loading error because source was a tracking URL (or
+      // fingerprinting, cryptomining, etc).
+      // We make a note of this sheet node by including it in a dedicated
+      // array of blocked tracking nodes under its parent document.
+      //
+      // Multiple sheet load instances might be tied to this request,
+      // we annotate each one linked to a valid owning element (node).
+      if (net::UrlClassifierFeatureFactory::IsClassifierBlockingErrorCode(
+              aStatus)) {
+        if (Document* doc = mLoader->GetDocument()) {
+          for (SheetLoadData* data = this; data; data = data->mNext) {
+            // owner node may be null but AddBlockTrackingNode can cope
+            doc->AddBlockedNodeByClassifier(data->mSheet->GetOwnerNode());
+          }
         }
       }
+      mLoader->SheetComplete(*this, aStatus);
     }
-    mLoader->SheetComplete(*this, aStatus);
     return NS_OK;
   }
 
   if (!aChannel) {
+    MOZ_ASSERT(NS_IsMainThread());
     mLoader->SheetComplete(*this, NS_OK);
     return NS_OK;
   }
@@ -688,10 +711,8 @@ nsresult SheetLoadData::VerifySheetReadyToParse(nsresult aStatus,
   // having a chrome URI.  (Whether or not chrome stylesheets come through
   // this codepath seems nondeterministic.)
   // Otherwise we want the potentially-HTTP-redirected URI.
-  nsCOMPtr<nsIURI> channelURI;
-  NS_GetFinalChannelURI(aChannel, getter_AddRefs(channelURI));
-
-  if (!channelURI || !originalURI) {
+  if (!aFinalChannelURI || !originalURI) {
+    MOZ_ASSERT(NS_IsMainThread());
     NS_ERROR("Someone just violated the nsIRequest contract");
     LOG_WARN(("  Channel without a URI.  Bad!"));
     mLoader->SheetComplete(*this, NS_ERROR_UNEXPECTED);
@@ -705,32 +726,33 @@ nsresult SheetLoadData::VerifySheetReadyToParse(nsresult aStatus,
     if (mUseSystemPrincipal) {
       result = secMan->GetSystemPrincipal(getter_AddRefs(principal));
     } else {
-      result = secMan->GetChannelResultPrincipal(aChannel,
-                                                 getter_AddRefs(principal));
+      if (aChannelResultPrincipal) {
+        principal = aChannelResultPrincipal;
+        result = NS_OK;
+      }
     }
   }
 
   if (NS_FAILED(result)) {
-    LOG_WARN(("  Couldn't get principal"));
-    mLoader->SheetComplete(*this, result);
+    if (NS_IsMainThread()) {
+      LOG_WARN(("  Couldn't get principal"));
+      mLoader->SheetComplete(*this, result);
+    }
     return NS_OK;
   }
 
   mSheet->SetPrincipal(principal);
 
-  if (mSheet->GetCORSMode() == CORS_NONE &&
-      !mTriggeringPrincipal->Subsumes(principal)) {
-    mIsCrossOriginNoCORS = true;
-  }
-
   // If it's an HTTP channel, we want to make sure this is not an
   // error document we got.
   if (nsCOMPtr<nsIHttpChannel> httpChannel = do_QueryInterface(aChannel)) {
     bool requestSucceeded;
     result = httpChannel->GetRequestSucceeded(&requestSucceeded);
     if (NS_SUCCEEDED(result) && !requestSucceeded) {
-      LOG(("  Load returned an error page"));
-      mLoader->SheetComplete(*this, NS_ERROR_NOT_AVAILABLE);
+      if (NS_IsMainThread()) {
+        LOG(("  Load returned an error page"));
+        mLoader->SheetComplete(*this, NS_ERROR_NOT_AVAILABLE);
+      }
       return NS_OK;
     }
 
@@ -753,6 +775,9 @@ nsresult SheetLoadData::VerifySheetReadyToParse(nsresult aStatus,
                    contentType.IsEmpty();
 
   if (!validType) {
+    if (!NS_IsMainThread()) {
+      return NS_OK;
+    }
     const char* errorMessage;
     uint32_t errorFlag;
     bool sameOrigin = true;
@@ -772,7 +797,8 @@ nsresult SheetLoadData::VerifySheetReadyToParse(nsresult aStatus,
     }
 
     AutoTArray<nsString, 2> strings;
-    CopyUTF8toUTF16(channelURI->GetSpecOrDefault(), *strings.AppendElement());
+    CopyUTF8toUTF16(aFinalChannelURI->GetSpecOrDefault(),
+                    *strings.AppendElement());
     CopyASCIItoUTF16(contentType, *strings.AppendElement());
 
     nsCOMPtr<nsIURI> referrer = ReferrerInfo()->GetOriginalReferrer();
@@ -791,6 +817,13 @@ nsresult SheetLoadData::VerifySheetReadyToParse(nsresult aStatus,
   SRIMetadata sriMetadata;
   mSheet->GetIntegrity(sriMetadata);
   if (!sriMetadata.IsEmpty()) {
+    if (!NS_IsMainThread()) {
+      // We dont process any further in OMT.
+      // This is because we have some main-thread only accesses below.
+      // We need to find a way to optimize this handling.
+      // See Bug 1882046.
+      return NS_OK;
+    }
     nsAutoCString sourceUri;
     if (mLoader->mDocument && mLoader->mDocument->GetDocumentURI()) {
       mLoader->mDocument->GetDocumentURI()->GetAsciiSpec(sourceUri);
@@ -815,9 +848,13 @@ nsresult SheetLoadData::VerifySheetReadyToParse(nsresult aStatus,
     }
   }
 
+  if (mSheet->GetCORSMode() == CORS_NONE &&
+      !mTriggeringPrincipal->Subsumes(principal)) {
+    mIsCrossOriginNoCORS = true;
+  }
   // Enough to set the URIs on mSheet, since any sibling datas we have share
   // the same mInner as mSheet and will thus get the same URI.
-  mSheet->SetURIs(channelURI, originalURI, channelURI);
+  mSheet->SetURIs(aFinalChannelURI, originalURI, aFinalChannelURI);
 
   ReferrerPolicy policy =
       nsContentUtils::GetReferrerPolicyFromChannel(aChannel);
@@ -1353,11 +1390,11 @@ nsresult Loader::LoadSheet(SheetLoadData& aLoadData, SheetState aSheetState,
 
 void Loader::AdjustPriority(const SheetLoadData& aLoadData,
                             nsIChannel* aChannel) {
-  if (!StaticPrefs::network_fetchpriority_enabled()) {
-    if (!aLoadData.ShouldDefer() && aLoadData.IsLinkRelPreload()) {
-      SheetLoadData::PrioritizeAsPreload(aChannel);
-    }
+  if (!aLoadData.ShouldDefer() && aLoadData.IsLinkRelPreload()) {
+    SheetLoadData::PrioritizeAsPreload(aChannel);
+  }
 
+  if (!StaticPrefs::network_fetchpriority_enabled()) {
     return;
   }
 
@@ -1367,32 +1404,27 @@ void Loader::AdjustPriority(const SheetLoadData& aLoadData,
     return;
   }
 
-  // Adjusting priorites is specified as implementation-defined. To align with
-  // other browsers for potentially important cases, some adjustments are made
-  // according to
-  // <https://web.dev/articles/fetch-priority#browser_priority_and_fetchpriority>.
-  const int32_t supportsPriority = [&]() {
+  // Adjusting priorites is specified as implementation-defined.
+  // See corresponding preferences in StaticPrefList.yaml for more context.
+  const int32_t supportsPriorityDelta = [&]() {
     if (aLoadData.ShouldDefer()) {
-      return nsISupportsPriority::PRIORITY_LOW;
+      return FETCH_PRIORITY_ADJUSTMENT_FOR(deferred_style,
+                                           aLoadData.mFetchPriority);
     }
-    switch (aLoadData.mFetchPriority) {
-      case FetchPriority::Auto: {
-        return nsISupportsPriority::PRIORITY_HIGHEST;
-      }
-      case FetchPriority::High: {
-        return nsISupportsPriority::PRIORITY_HIGHEST;
-      }
-      case FetchPriority::Low: {
-        return nsISupportsPriority::PRIORITY_HIGH;
-      }
+    if (aLoadData.IsLinkRelPreload()) {
+      return FETCH_PRIORITY_ADJUSTMENT_FOR(link_preload_style,
+                                           aLoadData.mFetchPriority);
     }
-
-    MOZ_ASSERT_UNREACHABLE();
-    return nsISupportsPriority::PRIORITY_HIGHEST;
+    return FETCH_PRIORITY_ADJUSTMENT_FOR(non_deferred_style,
+                                         aLoadData.mFetchPriority);
   }();
 
-  LogPriorityMapping(sCssLoaderLog, aLoadData.mFetchPriority, supportsPriority);
-  sp->SetPriority(supportsPriority);
+  sp->AdjustPriority(supportsPriorityDelta);
+#ifdef DEBUG
+  int32_t adjustedPriority;
+  sp->GetPriority(&adjustedPriority);
+  LogPriorityMapping(sCssLoaderLog, aLoadData.mFetchPriority, adjustedPriority);
+#endif
 }
 
 nsresult Loader::LoadSheetAsyncInternal(SheetLoadData& aLoadData,
@@ -1582,32 +1614,35 @@ nsresult Loader::LoadSheetAsyncInternal(SheetLoadData& aLoadData,
 /**
  * ParseSheet handles parsing the data stream.
  */
-Loader::Completed Loader::ParseSheet(const nsACString& aBytes,
-                                     SheetLoadData& aLoadData,
-                                     AllowAsyncParse aAllowAsync) {
+Loader::Completed Loader::ParseSheet(
+    const nsACString& aBytes, const RefPtr<SheetLoadDataHolder>& aLoadData,
+    AllowAsyncParse aAllowAsync) {
   LOG(("css::Loader::ParseSheet"));
-  if (aLoadData.mURI) {
-    LOG_URI("  Load succeeded for URI: '%s', parsing", aLoadData.mURI);
+  SheetLoadData* loadData = aLoadData->get();
+  MOZ_ASSERT(loadData);
+
+  if (loadData->mURI) {
+    LOG_URI("  Load succeeded for URI: '%s', parsing", loadData->mURI);
   }
   AUTO_PROFILER_LABEL_CATEGORY_PAIR_RELEVANT_FOR_JS(LAYOUT_CSSParsing);
 
   ++mParsedSheetCount;
 
-  aLoadData.mIsBeingParsed = true;
+  loadData->mIsBeingParsed = true;
 
-  StyleSheet* sheet = aLoadData.mSheet;
+  StyleSheet* sheet = loadData->mSheet;
   MOZ_ASSERT(sheet);
 
   // Some cases, like inline style and UA stylesheets, need to be parsed
   // synchronously. The former may trigger child loads, the latter must not.
-  if (aLoadData.mSyncLoad || aAllowAsync == AllowAsyncParse::No) {
-    sheet->ParseSheetSync(this, aBytes, &aLoadData);
-    aLoadData.mIsBeingParsed = false;
+  if (loadData->mSyncLoad || aAllowAsync == AllowAsyncParse::No) {
+    sheet->ParseSheetSync(this, aBytes, loadData);
+    loadData->mIsBeingParsed = false;
 
-    bool noPendingChildren = aLoadData.mPendingChildren == 0;
-    MOZ_ASSERT_IF(aLoadData.mSyncLoad, noPendingChildren);
+    bool noPendingChildren = loadData->mPendingChildren == 0;
+    MOZ_ASSERT_IF(loadData->mSyncLoad, noPendingChildren);
     if (noPendingChildren) {
-      SheetComplete(aLoadData, NS_OK);
+      SheetComplete(*loadData, NS_OK);
       return Completed::Yes;
     }
     return Completed::No;
@@ -1621,9 +1656,9 @@ Loader::Completed Loader::ParseSheet(const nsACString& aBytes,
   sheet->ParseSheet(*this, aBytes, aLoadData)
       ->Then(
           GetMainThreadSerialEventTarget(), __func__,
-          [loadData = RefPtr<SheetLoadData>(&aLoadData)](bool aDummy) {
+          [loadData = aLoadData](bool aDummy) {
             MOZ_ASSERT(NS_IsMainThread());
-            loadData->SheetFinishedParsingAsync();
+            loadData->get()->SheetFinishedParsingAsync();
           },
           [] { MOZ_CRASH("rejected parse promise"); });
   return Completed::No;
@@ -1847,7 +1882,10 @@ Result<Loader::LoadSheetResult, nsresult> Loader::LoadInlineStyle(
     // effects of inline stylesheets are visible immediately (aside from
     // @imports).
     NS_ConvertUTF16toUTF8 utf8(aBuffer);
-    completed = ParseSheet(utf8, *data, AllowAsyncParse::No);
+    RefPtr<SheetLoadDataHolder> holder(
+        new nsMainThreadPtrHolder<css::SheetLoadData>(__func__, data.get(),
+                                                      true));
+    completed = ParseSheet(utf8, holder, AllowAsyncParse::No);
     if (completed == Completed::Yes) {
       if (isWorthCaching) {
         mInlineSheets.InsertOrUpdate(aBuffer, std::move(sheet));
diff --git a/layout/style/Loader.h b/layout/style/Loader.h
index ba60218e94..70eefffb4a 100644
--- a/layout/style/Loader.h
+++ b/layout/style/Loader.h
@@ -590,7 +590,8 @@ class Loader final {
   //
   // If this function returns Completed::Yes, then ParseSheet also called
   // SheetComplete on aLoadData.
-  Completed ParseSheet(const nsACString&, SheetLoadData&, AllowAsyncParse);
+  Completed ParseSheet(const nsACString&, const RefPtr<SheetLoadDataHolder>&,
+                       AllowAsyncParse);
 
   // The load of the sheet in the load data is done, one way or another.
   // Do final cleanup.
@@ -646,7 +647,7 @@ class Loader final {
   uint32_t mPendingLoadCount = 0;
 
   // The number of stylesheets that we have parsed, for testing purposes.
-  uint32_t mParsedSheetCount = 0;
+  Atomic<uint32_t, MemoryOrdering::Relaxed> mParsedSheetCount{0};
 
   bool mEnabled = true;
 
diff --git a/layout/style/PseudoStyleType.h b/layout/style/PseudoStyleType.h
index 6804b500c3..88eb4e4cf8 100644
--- a/layout/style/PseudoStyleType.h
+++ b/layout/style/PseudoStyleType.h
@@ -7,6 +7,7 @@
 #ifndef mozilla_PseudoStyleType_h
 #define mozilla_PseudoStyleType_h
 
+#include <cstddef>
 #include <cstdint>
 #include <iosfwd>
 
diff --git a/layout/style/ServoBindings.toml b/layout/style/ServoBindings.toml
index cc6d13fb5e..20e1ca4116 100644
--- a/layout/style/ServoBindings.toml
+++ b/layout/style/ServoBindings.toml
@@ -186,16 +186,9 @@ allowlist-vars = [
     "NODE_.*",
     "ELEMENT_.*",
     "NS_FONT_.*",
-    "NS_STYLE_.*",
-    "NS_MATHML_.*",
-    "NS_RADIUS_.*",
-    "BORDER_COLOR_.*",
-    "BORDER_STYLE_.*",
     "CSS_PSEUDO_ELEMENT_.*",
     "SERVO_CSS_PSEUDO_ELEMENT_FLAGS_.*",
     "kNameSpaceID_.*",
-    "kGenericFont_.*",
-    "kPresContext_.*",
     "nsNameSpaceManager_.*",
     "GECKO_IS_NIGHTLY",
     "NS_SAME_AS_FOREGROUND_COLOR",
@@ -205,9 +198,7 @@ allowlist-vars = [
 # TODO(emilio): A bunch of types here can go away once we generate bindings and
 # structs together.
 allowlist-types = [
-    "ServoCssRules",
     "nsFontFaceRuleContainer",
-    "Matrix4x4Components",
     "mozilla::ComputedKeyframeValues",
     "mozilla::Keyframe",
     "mozilla::PropertyValuePair",
@@ -223,7 +214,6 @@ allowlist-types = [
     "mozilla::ServoElementSnapshot.*",
     "mozilla::ComputedStyle",
     "mozilla::StyleSheet",
-    "mozilla::ServoStyleSheetInner",
     "mozilla::ServoStyleSetSizes",
     "mozilla::ServoTraversalStatistics",
     "mozilla::css::LoaderReusableStyleSheets",
@@ -247,27 +237,14 @@ allowlist-types = [
     "mozilla::gfx::Float",
     "mozilla::gfx::FontVariation",
     "mozilla::gfx::FontPaletteValueSet",
-    "mozilla::gfx::FontPaletteValueSet::PaletteValeus",
     "mozilla::StyleImageLayerAttachment",
     "gfxFontFeature",
     "gfxFontVariation",
-    ".*ThreadSafe.*Holder",
-    "AnonymousContent",
-    "AudioContext",
-    "DefaultDelete",
-    "DOMIntersectionObserverEntry",
     "Element",
-    "mozilla::FontSizePrefs",
-    "FragmentOrURL",
-    "FrameRequestCallback",
-    "GeckoParserExtraData",
     "GeckoFontMetrics",
     "gfxFontFeatureValueSet",
-    "GridNamedArea",
     "mozilla::HalfCorner",
     "Image",
-    "ImageURL",
-    "Keyframe",
     "mozilla::MediumFeaturesChangedResult",
     "nsAttrName",
     "nsAttrValue",
@@ -280,15 +257,7 @@ allowlist-types = [
     "nsCSSPropertyID",
     "nsCSSPropertyIDSet",
     "nsCSSProps",
-    "nsCSSShadowArray",
     "nsCSSValue",
-    "nsCSSValueList",
-    "nsCSSValueList_heap",
-    "nsCSSValuePair_heap",
-    "nsCSSValuePairList",
-    "nsCSSValuePairList_heap",
-    "nsCSSValueTriplet_heap",
-    "nsCursorImage",
     "nsFont",
     "nsAtom",
     "nsDynamicAtom",
@@ -299,19 +268,11 @@ allowlist-types = [
     "nsSize",
     "nsStyleBackground",
     "nsStyleBorder",
-    "nsStyleColor",
     "nsStyleColumn",
     "nsStyleContent",
-    "nsStyleContentData",
-    "ComputedStyle",
-    "nsStyleCounterData",
     "nsStyleDisplay",
     "nsStyleEffects",
-    "nsStyleFilter",
     "nsStyleFont",
-    "nsStyleGradient",
-    "nsStyleGridTemplate",
-    "nsStyleImage",
     "nsStyleImageLayers",
     "nsStyleList",
     "nsStyleMargin",
@@ -319,37 +280,17 @@ allowlist-types = [
     "nsStylePadding",
     "nsStylePage",
     "nsStylePosition",
-    "nsStyleSides",
     "nsStyleSVG",
-    "nsStyleSVGOpacitySource",
     "nsStyleSVGReset",
     "nsStyleTable",
     "nsStyleTableBorder",
     "nsStyleText",
     "nsStyleTextReset",
     "nsStyleUIReset",
-    "nsStyleUnion",
     "nsStyleUI",
     "nsStyleVisibility",
     "nsStyleXUL",
     "nsTArrayHeader",
-    "Position",
-    "PropertyValuePair",
-    "Runnable",
-    "ServoAttrSnapshot",
-    "ServoComputedData",
-    "ServoComputedDataBorrowed",
-    "ServoElementSnapshot",
-    "ComputedStyleStrong",
-    "ComputedStyleBorrowed",
-    "ComputedStyleBorrowedOrNull",
-    "SheetParsingMode",
-    "StaticRefPtr",
-    "StyleAnimation",
-    "StyleGeometryBox",
-    "StyleShapeSource",
-    "StyleTransition",
-    "ThemeWidgetType",
     "mozilla::UniquePtr",
     "mozilla::DeclarationBlock",
     "mozilla::DefaultDelete",
@@ -430,6 +371,7 @@ opaque-types = [
 cbindgen-types = [
     { gecko = "StyleAnimationIterationCount", servo = "crate::values::computed::AnimationIterationCount" },
     { gecko = "StyleAnimationTimeline", servo = "crate::values::computed::AnimationTimeline" },
+    { gecko = "StyleTransitionBehavior", servo = "crate::values::computed::TransitionBehavior" },
     { gecko = "StyleAppearance", servo = "crate::values::specified::Appearance" },
     { gecko = "StyleAspectRatio", servo = "crate::values::computed::position::AspectRatio" },
     { gecko = "StyleAtom", servo = "crate::Atom" },
diff --git a/layout/style/ServoCSSParser.cpp b/layout/style/ServoCSSParser.cpp
index 92e1271f2c..89f17f1733 100644
--- a/layout/style/ServoCSSParser.cpp
+++ b/layout/style/ServoCSSParser.cpp
@@ -33,6 +33,16 @@ bool ServoCSSParser::ComputeColor(ServoStyleSet* aStyleSet,
 }
 
 /* static */
+bool ServoCSSParser::ColorTo(const nsACString& aFromColor,
+                             const nsACString& aToColorSpace,
+                             nsACString* aResultColor,
+                             nsTArray<float>* aResultComponents,
+                             bool* aResultAdjusted, css::Loader* aLoader) {
+  return Servo_ColorTo(&aFromColor, &aToColorSpace, aResultColor,
+                       aResultComponents, aResultAdjusted, aLoader);
+}
+
+/* static */
 already_AddRefed<StyleLockedDeclarationBlock> ServoCSSParser::ParseProperty(
     nsCSSPropertyID aProperty, const nsACString& aValue,
     const ParsingEnvironment& aParsingEnvironment,
diff --git a/layout/style/ServoCSSParser.h b/layout/style/ServoCSSParser.h
index 4bbde6a0e8..583a2eebd9 100644
--- a/layout/style/ServoCSSParser.h
+++ b/layout/style/ServoCSSParser.h
@@ -80,6 +80,27 @@ class ServoCSSParser {
                            css::Loader* aLoader = nullptr);
 
   /**
+  * Takes a CSS <color> and convert it to another color space.
+  *
+  * @param aStyleSet The style set whose nsPresContext will be used to
+  *   compute system colors and other special color values.
+  * @param aFromColor The CSS <color> we use to convert from.
+  * @param aToColorSpace The CSS <color-space> to convert the color into.
+  * @param aResultColor The resulting converted color value.
+  * @param aResultAdjusted Whether the color was adjusted to fit into the SRGB
+      color space.
+  * @param aLoader The CSS loader for document we're parsing a color for,
+  *   so that parse errors can be reported to the console. If nullptr, errors
+  *   won't be reported to the console.
+  * @return Whether aFromColor and aToColorSpace was successfully parsed and
+  *   aResultColor and aResultAdjusted was set.
+  */
+  static bool ColorTo(const nsACString& aFromColor,
+                      const nsACString& aToColorSpace, nsACString* aResultColor,
+                      nsTArray<float>* aResultComponents, bool* aResultAdjusted,
+                      css::Loader* aLoader = nullptr);
+
+  /**
    * Parse a string representing a CSS property value into a
    * StyleLockedDeclarationBlock.
    *
diff --git a/layout/style/ServoStyleConstsInlines.h b/layout/style/ServoStyleConstsInlines.h
index b6a574037a..1985e8fbeb 100644
--- a/layout/style/ServoStyleConstsInlines.h
+++ b/layout/style/ServoStyleConstsInlines.h
@@ -507,20 +507,15 @@ StyleCSSPixelLength StyleCSSPixelLength::ScaledBy(float aScale) const {
   return FromPixels(ToCSSPixels() * aScale);
 }
 
-nscoord StyleCSSPixelLength::ToAppUnits() const {
-  // We want to resolve the length part of the calc() expression rounding 0.5
-  // away from zero, instead of the default behavior of
-  // NSToCoordRound{,WithClamp} which do floor(x + 0.5).
-  //
-  // This is what the rust code in the app_units crate does, and not doing this
-  // would regress bug 1323735, for example.
-  //
-  // FIXME(emilio, bug 1528114): Probably we should do something smarter.
-  if (IsZero()) {
-    // Avoid the expensive FP math below.
-    return 0;
-  }
-  float length = _0 * float(mozilla::AppUnitsPerCSSPixel());
+namespace detail {
+static inline nscoord DefaultPercentLengthToAppUnits(float aPixelLength) {
+  return NSToCoordTruncClamped(aPixelLength);
+}
+
+static inline nscoord DefaultLengthToAppUnits(float aPixelLength) {
+  // We want to round lengths rounding 0.5 away from zero, instead of the
+  // default behavior of NSToCoordRound{,WithClamp} which do floor(x + 0.5).
+  float length = aPixelLength * float(mozilla::AppUnitsPerCSSPixel());
   if (length >= float(nscoord_MAX)) {
     return nscoord_MAX;
   }
@@ -529,6 +524,15 @@ nscoord StyleCSSPixelLength::ToAppUnits() const {
   }
   return NSToIntRound(length);
 }
+}  // namespace detail
+
+nscoord StyleCSSPixelLength::ToAppUnits() const {
+  if (IsZero()) {
+    // Avoid the expensive FP math below.
+    return 0;
+  }
+  return detail::DefaultLengthToAppUnits(_0);
+}
 
 bool LengthPercentage::IsLength() const { return Tag() == TAG_LENGTH; }
 
@@ -693,6 +697,11 @@ CSSCoord StyleCalcLengthPercentage::ResolveToCSSPixels(CSSCoord aBasis) const {
   return Servo_ResolveCalcLengthPercentage(this, aBasis);
 }
 
+nscoord StyleCalcLengthPercentage::Resolve(nscoord aBasis) const {
+  return detail::DefaultLengthToAppUnits(
+      ResolveToCSSPixels(CSSPixel::FromAppUnits(aBasis)));
+}
+
 template <>
 void StyleCalcNode::ScaleLengthsBy(float);
 
@@ -708,20 +717,18 @@ CSSCoord LengthPercentage::ResolveToCSSPixels(CSSCoord aPercentageBasis) const {
 
 template <typename T>
 CSSCoord LengthPercentage::ResolveToCSSPixelsWith(T aPercentageGetter) const {
-  static_assert(std::is_same<decltype(aPercentageGetter()), CSSCoord>::value,
-                "Should return CSS pixels");
+  static_assert(std::is_same_v<decltype(aPercentageGetter()), CSSCoord>);
   if (ConvertsToLength()) {
     return ToLengthInCSSPixels();
   }
   return ResolveToCSSPixels(aPercentageGetter());
 }
 
-template <typename T, typename U>
-nscoord LengthPercentage::Resolve(T aPercentageGetter, U aRounder) const {
-  static_assert(std::is_same<decltype(aPercentageGetter()), nscoord>::value,
-                "Should return app units");
-  static_assert(std::is_same<decltype(aRounder(1.0f)), nscoord>::value,
-                "Should return app units");
+template <typename T, typename PercentRounder>
+nscoord LengthPercentage::Resolve(T aPercentageGetter,
+                                  PercentRounder aPercentRounder) const {
+  static_assert(std::is_same_v<decltype(aPercentageGetter()), nscoord>);
+  static_assert(std::is_same_v<decltype(aPercentRounder(1.0f)), nscoord>);
   if (ConvertsToLength()) {
     return ToLength();
   }
@@ -730,29 +737,26 @@ nscoord LengthPercentage::Resolve(T aPercentageGetter, U aRounder) const {
   }
   nscoord basis = aPercentageGetter();
   if (IsPercentage()) {
-    return aRounder(basis * AsPercentage()._0);
+    return aPercentRounder(basis * AsPercentage()._0);
   }
-  return AsCalc().Resolve(basis, aRounder);
+  return AsCalc().Resolve(basis);
 }
 
-// Note: the static_cast<> wrappers below are needed to disambiguate between
-// the versions of NSToCoordTruncClamped that take float vs. double as the arg.
 nscoord LengthPercentage::Resolve(nscoord aPercentageBasis) const {
   return Resolve([=] { return aPercentageBasis; },
-                 static_cast<nscoord (*)(float)>(NSToCoordTruncClamped));
+                 detail::DefaultPercentLengthToAppUnits);
 }
 
 template <typename T>
 nscoord LengthPercentage::Resolve(T aPercentageGetter) const {
-  return Resolve(aPercentageGetter,
-                 static_cast<nscoord (*)(float)>(NSToCoordTruncClamped));
+  return Resolve(aPercentageGetter, detail::DefaultPercentLengthToAppUnits);
 }
 
-template <typename T>
+template <typename PercentRounder>
 nscoord LengthPercentage::Resolve(nscoord aPercentageBasis,
-                                  T aPercentageRounder) const {
+                                  PercentRounder aPercentRounder) const {
   return Resolve([aPercentageBasis] { return aPercentageBasis; },
-                 aPercentageRounder);
+                 aPercentRounder);
 }
 
 void LengthPercentage::ScaleLengthsBy(float aScale) {
diff --git a/layout/style/ServoStyleSet.h b/layout/style/ServoStyleSet.h
index d7225349cc..eee6cba0f7 100644
--- a/layout/style/ServoStyleSet.h
+++ b/layout/style/ServoStyleSet.h
@@ -686,8 +686,8 @@ class ServoStyleSet {
 
   // Stores pointers to our cached ComputedStyles for non-inheriting anonymous
   // boxes.
-  EnumeratedArray<nsCSSAnonBoxes::NonInheriting,
-                  nsCSSAnonBoxes::NonInheriting::_Count, RefPtr<ComputedStyle>>
+  EnumeratedArray<nsCSSAnonBoxes::NonInheriting, RefPtr<ComputedStyle>,
+                  size_t(nsCSSAnonBoxes::NonInheriting::_Count)>
       mNonInheritingComputedStyles;
 
  public:
diff --git a/layout/style/SheetLoadData.h b/layout/style/SheetLoadData.h
index c817e4c1f3..6621af35bd 100644
--- a/layout/style/SheetLoadData.h
+++ b/layout/style/SheetLoadData.h
@@ -90,7 +90,9 @@ class SheetLoadData final
   // so aBytes1 and aBytes2 refer to those pieces.
   nsresult VerifySheetReadyToParse(nsresult aStatus, const nsACString& aBytes1,
                                    const nsACString& aBytes2,
-                                   nsIChannel* aChannel);
+                                   nsIChannel* aChannel,
+                                   nsIURI* aFinalChannelURI,
+                                   nsIPrincipal* aPrincipal);
 
   NS_DECL_ISUPPORTS
 
@@ -237,6 +239,8 @@ class SheetLoadData final
   // listening for the load.
   bool mIntentionallyDropped = false;
 
+  const bool mRecordErrors;
+
   bool ShouldDefer() const { return mWasAlternate || !mMediaMatched; }
 
   RefPtr<StyleSheet> ValueForCache() const;
diff --git a/layout/style/StreamLoader.cpp b/layout/style/StreamLoader.cpp
index 3e8bd37d76..3c614d7d0c 100644
--- a/layout/style/StreamLoader.cpp
+++ b/layout/style/StreamLoader.cpp
@@ -5,8 +5,9 @@
  * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
 
 #include "mozilla/css/StreamLoader.h"
-
+#include "mozilla/StaticPrefs_network.h"
 #include "mozilla/Encoding.h"
+#include "mozilla/glean/GleanMetrics.h"
 #include "mozilla/TaskQueue.h"
 #include "nsContentUtils.h"
 #include "nsIChannel.h"
@@ -14,16 +15,21 @@
 #include "nsIThreadRetargetableRequest.h"
 #include "nsIStreamTransportService.h"
 #include "nsNetCID.h"
+#include "nsNetUtil.h"
+#include "nsProxyRelease.h"
 #include "nsServiceManagerUtils.h"
 
 namespace mozilla::css {
 
 StreamLoader::StreamLoader(SheetLoadData& aSheetLoadData)
-    : mSheetLoadData(&aSheetLoadData), mStatus(NS_OK) {}
+    : mSheetLoadData(&aSheetLoadData),
+      mStatus(NS_OK),
+      mMainThreadSheetLoadData(new nsMainThreadPtrHolder<SheetLoadData>(
+          "StreamLoader::SheetLoadData", mSheetLoadData, false)) {}
 
 StreamLoader::~StreamLoader() {
 #ifdef NIGHTLY_BUILD
-  MOZ_RELEASE_ASSERT(mOnStopRequestCalled || mChannelOpenFailed);
+  MOZ_RELEASE_ASSERT(mOnStopProcessingDone || mChannelOpenFailed);
 #endif
 }
 
@@ -34,6 +40,7 @@ NS_IMPL_ISUPPORTS(StreamLoader, nsIStreamListener,
 NS_IMETHODIMP
 StreamLoader::OnStartRequest(nsIRequest* aRequest) {
   MOZ_ASSERT(aRequest);
+  mRequest = aRequest;
   mSheetLoadData->NotifyStart(aRequest);
 
   // It's kinda bad to let Web content send a number that results
@@ -52,6 +59,12 @@ StreamLoader::OnStartRequest(nsIRequest* aRequest) {
         return (mStatus = NS_ERROR_OUT_OF_MEMORY);
       }
     }
+    NS_GetFinalChannelURI(channel, getter_AddRefs(mFinalChannelURI));
+    nsIScriptSecurityManager* secMan = nsContentUtils::GetSecurityManager();
+    // we dont return on error here as the error is handled in
+    // SheetLoadData::VerifySheetReadyToParse
+    Unused << secMan->GetChannelResultPrincipal(
+        channel, getter_AddRefs(mChannelResultPrincipal));
   }
   if (nsCOMPtr<nsIThreadRetargetableRequest> rr = do_QueryInterface(aRequest)) {
     nsCOMPtr<nsIEventTarget> sts =
@@ -73,6 +86,13 @@ StreamLoader::OnStartRequest(nsIRequest* aRequest) {
     return *info.mExpirationTime;
   }();
 
+  // We need to block block resolution of parse promise until we receive
+  // OnStopRequest on Main thread. This is necessary because parse promise
+  // resolution fires OnLoad event OnLoad event must not be dispatched until
+  // OnStopRequest in main thread is processed, for stuff like performance
+  // resource entries.
+  mSheetLoadData->mSheet->BlockParsePromise();
+
   return NS_OK;
 }
 
@@ -81,39 +101,80 @@ StreamLoader::CheckListenerChain() { return NS_OK; }
 
 NS_IMETHODIMP
 StreamLoader::OnStopRequest(nsIRequest* aRequest, nsresult aStatus) {
-#ifdef NIGHTLY_BUILD
-  MOZ_RELEASE_ASSERT(!mOnStopRequestCalled);
-  mOnStopRequestCalled = true;
-#endif
+  MOZ_ASSERT_IF(!StaticPrefs::network_send_OnDataFinished_cssLoader(),
+                !mOnStopProcessingDone);
+
+  // StreamLoader::OnStopRequest can get triggered twice for a request.
+  // Once from the path
+  // nsIThreadRetargetableStreamListener::OnDataFinished->StreamLoader::OnDataFinished
+  // (non-main thread)  and
+  // once from nsIRequestObserver::OnStopRequest path (main thread). It is
+  // guaranteed that we will always get
+  // nsIThreadRetargetableStreamListener::OnDataFinished trigger first and this
+  // is always followed by nsIRequestObserver::OnStopRequest
+
+  // If we are executing OnStopRequest OMT, we need to block resolution of parse
+  // promise and unblock again if we are executing this in main thread.
+  // Resolution of parse promise fires onLoadEvent and this should not happen
+  // before main thread OnStopRequest is dispatched.
+  if (NS_IsMainThread()) {
+    if (mOnDataFinishedTime) {
+      // collect telemetry for the delta between OnDataFinished and
+      // OnStopRequest
+      TimeDuration delta = (TimeStamp::Now() - mOnDataFinishedTime);
+      glean::networking::http_content_cssloader_ondatafinished_to_onstop_delay
+          .AccumulateRawDuration(delta);
+    }
+    mSheetLoadData->mSheet->UnblockParsePromise();
+  }
+
+  if (mOnStopProcessingDone) {
+    return NS_OK;
+  }
+  mOnStopProcessingDone = true;
 
   nsresult rv = mStatus;
   // Decoded data
   nsCString utf8String;
   {
-    // Hold the nsStringBuffer for the bytes from the stack to ensure release
-    // no matter which return branch is taken.
-    nsCString bytes = std::move(mBytes);
-
     nsCOMPtr<nsIChannel> channel = do_QueryInterface(aRequest);
 
     if (NS_FAILED(mStatus)) {
-      mSheetLoadData->VerifySheetReadyToParse(mStatus, ""_ns, ""_ns, channel);
+      mSheetLoadData->VerifySheetReadyToParse(mStatus, ""_ns, ""_ns, channel,
+                                              mFinalChannelURI,
+                                              mChannelResultPrincipal);
+
+      if (!NS_IsMainThread()) {
+        // When processing OMT, we have code paths in VerifySheetReadyToParse
+        // that are main-thread only. We bail on such scenarios and continue
+        // processing them on main thread OnStopRequest.
+        mOnStopProcessingDone = false;
+      }
       return mStatus;
     }
 
-    rv = mSheetLoadData->VerifySheetReadyToParse(aStatus, mBOMBytes, bytes,
-                                                 channel);
+    rv = mSheetLoadData->VerifySheetReadyToParse(aStatus, mBOMBytes, mBytes,
+                                                 channel, mFinalChannelURI,
+                                                 mChannelResultPrincipal);
     if (rv != NS_OK_PARSE_SHEET) {
+      if (!NS_IsMainThread()) {
+        mOnStopProcessingDone = false;
+      }
       return rv;
     }
 
-    // BOM detection generally happens during the write callback, but that won't
-    // have happened if fewer than three bytes were received.
+    // At this point all the conditions that requires us to run on main
+    // are checked in VerifySheetReadyToParse
+
+    // BOM detection generally happens during the write callback, but that
+    // won't have happened if fewer than three bytes were received.
     if (mEncodingFromBOM.isNothing()) {
       HandleBOM();
       MOZ_ASSERT(mEncodingFromBOM.isSome());
     }
-
+    // Hold the nsStringBuffer for the bytes from the stack to ensure release
+    // after its scope ends
+    nsCString bytes = std::move(mBytes);
     // The BOM handling has happened, but we still may not have an encoding if
     // there was no BOM. Ensure we have one.
     const Encoding* encoding = mEncodingFromBOM.value();
@@ -142,9 +203,11 @@ StreamLoader::OnStopRequest(nsIRequest* aRequest, nsresult aStatus) {
   // For reasons I don't understand, factoring the below lines into
   // a method on SheetLoadData resulted in a linker error. Hence,
   // accessing fields of mSheetLoadData from here.
-  mSheetLoadData->mLoader->ParseSheet(utf8String, *mSheetLoadData,
+  mSheetLoadData->mLoader->ParseSheet(utf8String, mMainThreadSheetLoadData,
                                       Loader::AllowAsyncParse::Yes);
 
+  mRequest = nullptr;
+
   return NS_OK;
 }
 
@@ -159,9 +222,6 @@ StreamLoader::OnDataAvailable(nsIRequest*, nsIInputStream* aInputStream,
   return aInputStream->ReadSegments(WriteSegmentFun, this, aCount, &dummy);
 }
 
-NS_IMETHODIMP
-StreamLoader::OnDataFinished(nsresult aStatus) { return NS_OK; }
-
 void StreamLoader::HandleBOM() {
   MOZ_ASSERT(mEncodingFromBOM.isNothing());
   MOZ_ASSERT(mBytes.IsEmpty());
@@ -176,6 +236,18 @@ void StreamLoader::HandleBOM() {
   mBOMBytes.Truncate(bomLength);
 }
 
+NS_IMETHODIMP
+StreamLoader::OnDataFinished(nsresult aResult) {
+  if (StaticPrefs::network_send_OnDataFinished_cssLoader()) {
+    MOZ_ASSERT(mOnDataFinishedTime.IsNull(),
+               "OnDataFinished should only be called once");
+    mOnDataFinishedTime = TimeStamp::Now();
+    return OnStopRequest(mRequest, aResult);
+  }
+
+  return NS_OK;
+}
+
 nsresult StreamLoader::WriteSegmentFun(nsIInputStream*, void* aClosure,
                                        const char* aSegment, uint32_t,
                                        uint32_t aCount, uint32_t* aWriteCount) {
diff --git a/layout/style/StreamLoader.h b/layout/style/StreamLoader.h
index a34117625a..e940fc7936 100644
--- a/layout/style/StreamLoader.h
+++ b/layout/style/StreamLoader.h
@@ -9,6 +9,7 @@
 
 #include "nsIStreamListener.h"
 #include "nsIThreadRetargetableStreamListener.h"
+#include "nsIURI.h"
 #include "nsString.h"
 #include "mozilla/css/SheetLoadData.h"
 #include "mozilla/Assertions.h"
@@ -52,10 +53,17 @@ class StreamLoader : public nsIThreadRetargetableStreamListener {
   // mBytes, and store all subsequent data in that buffer.
   nsCString mBytes;
   nsAutoCStringN<3> mBOMBytes;
+  nsCOMPtr<nsIRequest> mRequest;
+  nsCOMPtr<nsIURI> mFinalChannelURI;
+  nsCOMPtr<nsIPrincipal> mChannelResultPrincipal;
+  // flag to indicate that we can skip processing of data in OnStopRequest
+  bool mOnStopProcessingDone{false};
+  RefPtr<SheetLoadDataHolder> mMainThreadSheetLoadData;
+
+  mozilla::TimeStamp mOnDataFinishedTime;
 
 #ifdef NIGHTLY_BUILD
   bool mChannelOpenFailed = false;
-  bool mOnStopRequestCalled = false;
 #endif
 };
 
diff --git a/layout/style/StyleSheet.cpp b/layout/style/StyleSheet.cpp
index 494618d879..b1ce1d66e2 100644
--- a/layout/style/StyleSheet.cpp
+++ b/layout/style/StyleSheet.cpp
@@ -28,7 +28,6 @@
 #include "mozilla/css/SheetLoadData.h"
 
 #include "mozAutoDocUpdate.h"
-#include "SheetLoadData.h"
 
 namespace mozilla {
 
@@ -136,8 +135,12 @@ already_AddRefed<StyleSheet> StyleSheet::Constructor(
 
   // 3. Set the sheet's disabled flag according to aOptions.
   sheet->SetDisabled(aOptions.mDisabled);
+  sheet->SetURLExtraData();
   sheet->SetComplete();
 
+  sheet->ReplaceSync(""_ns, aRv);
+  MOZ_ASSERT(!aRv.Failed());
+
   // 4. Return sheet.
   return sheet.forget();
 }
@@ -740,7 +743,9 @@ already_AddRefed<dom::Promise> StyleSheet::Replace(const nsACString& aText,
   loadData->mIsBeingParsed = true;
   MOZ_ASSERT(!mReplacePromise);
   mReplacePromise = promise;
-  ParseSheet(*loader, aText, *loadData)
+  RefPtr<css::SheetLoadDataHolder> holder(
+      new css::SheetLoadDataHolder(__func__, loadData, false));
+  ParseSheet(*loader, aText, holder)
       ->Then(
           target, __func__,
           [loadData] { loadData->SheetFinishedParsingAsync(); },
@@ -769,7 +774,6 @@ void StyleSheet::ReplaceSync(const nsACString& aText, ErrorResult& aRv) {
   // 3. Parse aText into rules.
   // 4. If rules contain @imports, skip them and continue parsing.
   auto* loader = mConstructorDocument->CSSLoader();
-  SetURLExtraData();
   RefPtr<const StyleStylesheetContents> rawContent =
       Servo_StyleSheet_FromUTF8Bytes(
           loader, this,
@@ -1159,28 +1163,19 @@ already_AddRefed<StyleSheet> StyleSheet::CreateEmptyChildSheet(
   return child.forget();
 }
 
-// We disable parallel stylesheet parsing if the browser is recording CSS errors
-// (which parallel parsing can't handle).
-static bool AllowParallelParse(css::Loader& aLoader, URLExtraData* aUrlData) {
-  Document* doc = aLoader.GetDocument();
-  if (doc && css::ErrorReporter::ShouldReportErrors(*doc)) {
-    return false;
-  }
-  // Otherwise we can parse in parallel.
-  return true;
-}
-
 RefPtr<StyleSheetParsePromise> StyleSheet::ParseSheet(
     css::Loader& aLoader, const nsACString& aBytes,
-    css::SheetLoadData& aLoadData) {
+    const RefPtr<css::SheetLoadDataHolder>& aLoadData) {
   MOZ_ASSERT(mParsePromise.IsEmpty());
+  MOZ_ASSERT_IF(NS_IsMainThread(), mAsyncParseBlockers == 0);
+
   RefPtr<StyleSheetParsePromise> p = mParsePromise.Ensure(__func__);
-  if (!aLoadData.ShouldDefer()) {
+  if (!aLoadData->get()->ShouldDefer()) {
     mParsePromise.SetTaskPriority(nsIRunnablePriority::PRIORITY_RENDER_BLOCKING,
                                   __func__);
   }
+  BlockParsePromise();
   SetURLExtraData();
-
   // @import rules are disallowed due to this decision:
   // https://github.com/WICG/construct-stylesheets/issues/119#issuecomment-588352418
   // We may allow @import rules again in the future.
@@ -1191,26 +1186,26 @@ RefPtr<StyleSheetParsePromise> StyleSheet::ParseSheet(
   const bool shouldRecordCounters =
       aLoader.GetDocument() && aLoader.GetDocument()->GetStyleUseCounters() &&
       !urlData->ChromeRulesEnabled();
-  if (!AllowParallelParse(aLoader, urlData)) {
+
+  if (aLoadData->get()->mRecordErrors) {
+    MOZ_ASSERT(NS_IsMainThread());
     UniquePtr<StyleUseCounters> counters;
     if (shouldRecordCounters) {
       counters.reset(Servo_UseCounters_Create());
     }
-
     RefPtr<StyleStylesheetContents> contents =
         Servo_StyleSheet_FromUTF8Bytes(
-            &aLoader, this, &aLoadData, &aBytes, mParsingMode, urlData,
-            aLoadData.mCompatMode,
+            &aLoader, this, aLoadData->get(), &aBytes, mParsingMode, urlData,
+            aLoadData->get()->mCompatMode,
             /* reusable_sheets = */ nullptr, counters.get(), allowImportRules,
             StyleSanitizationKind::None,
             /* sanitized_output = */ nullptr)
             .Consume();
     FinishAsyncParse(contents.forget(), std::move(counters));
   } else {
-    auto holder = MakeRefPtr<css::SheetLoadDataHolder>(__func__, &aLoadData);
-    Servo_StyleSheet_FromUTF8BytesAsync(holder, urlData, &aBytes, mParsingMode,
-                                        aLoadData.mCompatMode,
-                                        shouldRecordCounters, allowImportRules);
+    Servo_StyleSheet_FromUTF8BytesAsync(
+        aLoadData, urlData, &aBytes, mParsingMode,
+        aLoadData->get()->mCompatMode, shouldRecordCounters, allowImportRules);
   }
 
   return p;
@@ -1224,7 +1219,7 @@ void StyleSheet::FinishAsyncParse(
   Inner().mContents = aSheetContents;
   Inner().mUseCounters = std::move(aUseCounters);
   FixUpRuleListAfterContentsChangeIfNeeded();
-  mParsePromise.Resolve(true, __func__);
+  UnblockParsePromise();
 }
 
 void StyleSheet::ParseSheetSync(
diff --git a/layout/style/StyleSheet.h b/layout/style/StyleSheet.h
index 1dbcad1e01..873ff2f4fc 100644
--- a/layout/style/StyleSheet.h
+++ b/layout/style/StyleSheet.h
@@ -7,6 +7,7 @@
 #ifndef mozilla_StyleSheet_h
 #define mozilla_StyleSheet_h
 
+#include "mozilla/Assertions.h"
 #include "mozilla/css/SheetParsingMode.h"
 #include "mozilla/dom/CSSStyleSheetBinding.h"
 #include "mozilla/dom/SRIMetadata.h"
@@ -15,11 +16,13 @@
 #include "mozilla/RefPtr.h"
 #include "mozilla/ServoBindingTypes.h"
 #include "mozilla/ServoTypes.h"
+#include "mozilla/StaticPrefs_network.h"
 #include "mozilla/StyleSheetInfo.h"
 #include "nsICSSLoaderObserver.h"
 #include "nsIPrincipal.h"
 #include "nsWrapperCache.h"
 #include "nsStringFwd.h"
+#include "nsProxyRelease.h"
 
 class nsIGlobalObject;
 class nsINode;
@@ -44,6 +47,7 @@ class Loader;
 class LoaderReusableStyleSheets;
 class Rule;
 class SheetLoadData;
+using SheetLoadDataHolder = nsMainThreadPtrHolder<SheetLoadData>;
 }  // namespace css
 
 namespace dom {
@@ -112,9 +116,9 @@ class StyleSheet final : public nsICSSLoaderObserver, public nsWrapperCache {
   // SheetLoadData for this stylesheet.
   // NOTE: ParseSheet can run synchronously or asynchronously
   //       based on the result of `AllowParallelParse`
-  RefPtr<StyleSheetParsePromise> ParseSheet(css::Loader&,
-                                            const nsACString& aBytes,
-                                            css::SheetLoadData&);
+  RefPtr<StyleSheetParsePromise> ParseSheet(
+      css::Loader&, const nsACString& aBytes,
+      const RefPtr<css::SheetLoadDataHolder>& aLoadData);
 
   // Common code that needs to be called after servo finishes parsing. This is
   // shared between the parallel and sequential paths.
@@ -301,7 +305,7 @@ class StyleSheet final : public nsICSSLoaderObserver, public nsWrapperCache {
    */
   void SetPrincipal(nsIPrincipal* aPrincipal) {
     StyleSheetInfo& info = Inner();
-    MOZ_ASSERT(!info.mPrincipalSet, "Should only set principal once");
+    MOZ_ASSERT_IF(info.mPrincipalSet, info.mPrincipal == aPrincipal);
     if (aPrincipal) {
       info.mPrincipal = aPrincipal;
 #ifdef DEBUG
@@ -468,6 +472,23 @@ class StyleSheet final : public nsICSSLoaderObserver, public nsWrapperCache {
   // Gets the relevant global if exists.
   nsISupports* GetRelevantGlobal() const;
 
+  // Blocks/Unblocks resolution of parse promise
+  void BlockParsePromise() {
+#ifdef MOZ_DIAGNOSTIC_ASSERT_ENABLED
+    uint32_t count =
+#endif
+        ++mAsyncParseBlockers;
+    MOZ_DIAGNOSTIC_ASSERT(count);
+  }
+
+  void UnblockParsePromise() {
+    uint32_t count = --mAsyncParseBlockers;
+    MOZ_DIAGNOSTIC_ASSERT(count != UINT32_MAX);
+    if (!count && !mParsePromise.IsEmpty()) {
+      mParsePromise.Resolve(true, __func__);
+    }
+  }
+
  private:
   void SetModifiedRules() {
     mState |= State::ModifiedRules | State::ModifiedRulesForDevtools;
@@ -591,6 +612,8 @@ class StyleSheet final : public nsICSSLoaderObserver, public nsWrapperCache {
 
   State mState;
 
+  Atomic<uint32_t, ReleaseAcquire> mAsyncParseBlockers{0};
+
   // Core information we get from parsed sheets, which are shared amongst
   // StyleSheet clones.
   //
diff --git a/layout/style/contenteditable.css b/layout/style/contenteditable.css
index a2e2ca8712..7e9a197740 100644
--- a/layout/style/contenteditable.css
+++ b/layout/style/contenteditable.css
@@ -77,10 +77,6 @@ input[contenteditable="true"][type="hidden"] {
   visibility: visible !important;
 }
 
-*|*::-moz-display-comboboxcontrol-frame {
-  user-select: text;
-}
-
 option:read-write {
   user-select: text;
 }
diff --git a/layout/style/crashtests/1397439-1.html b/layout/style/crashtests/1397439-1.html
deleted file mode 100644
index b617f8e0ed..0000000000
--- a/layout/style/crashtests/1397439-1.html
+++ /dev/null
@@ -1,6 +0,0 @@
-<!DOCTYPE html>
-<math>
-<mstyle scriptlevel=101>
-<mstyle scriptlevel=-204>
-</math>
-
diff --git a/layout/style/crashtests/1403465.html b/layout/style/crashtests/1403465.html
deleted file mode 100644
index 924392757b..0000000000
--- a/layout/style/crashtests/1403465.html
+++ /dev/null
@@ -1,24 +0,0 @@
-<!DOCTYPE html>
-<html>
-<body>
-  <math class="hidden">
-    <mi>x</mi>
-    <mo>=</mo>
-  </math>
-<script>
-window.onload = function() {
-  let s = document.createElement("style");
-  s.textContent = `
-    body {
-      line-height: 1.42857143;
-    }
-
-    .hidden {
-      display: none;
-    }
-  `;
-  document.body.appendChild(s);
-};
-</script>
-</body>
-</html>
diff --git a/layout/style/crashtests/411603-1.html b/layout/style/crashtests/411603-1.html
deleted file mode 100644
index 596565fbc3..0000000000
--- a/layout/style/crashtests/411603-1.html
+++ /dev/null
@@ -1,7 +0,0 @@
-<html xmlns="http://www.w3.org/1999/xhtml" xmlns:math="http://www.w3.org/1998/Math/MathML">
-<head>
-</head>
-<body onload="document.getElementById('ms').setAttribute('scriptminsize', '9em');">
-<math:mstyle id="ms" /><span />
-</body>
-</html>
diff --git a/layout/style/crashtests/413274-1.xhtml b/layout/style/crashtests/413274-1.xhtml
deleted file mode 100644
index 19d8fab0fd..0000000000
--- a/layout/style/crashtests/413274-1.xhtml
+++ /dev/null
@@ -1,18 +0,0 @@
-<html xmlns="http://www.w3.org/1999/xhtml">
-<head>
-</head>
-<body>
-
-<math xmlns="http://www.w3.org/1998/Math/MathML">
-  <mstyle scriptsizemultiplier="8205" scriptlevel="15">
-    <mroot>
-      <mrow/>
-      <mrow>
-        <span xmlns="http://www.w3.org/1999/xhtml"/>
-      </mrow>
-    </mroot>
-  </mstyle>
-</math>
-
-</body>
-</html>
diff --git a/layout/style/crashtests/418007-1.xhtml b/layout/style/crashtests/418007-1.xhtml
deleted file mode 100644
index f07a693444..0000000000
--- a/layout/style/crashtests/418007-1.xhtml
+++ /dev/null
@@ -1,24 +0,0 @@
-<html xmlns="http://www.w3.org/1999/xhtml">
-<head></head>
-<body>
-
-<math xmlns="http://www.w3.org/1998/Math/MathML">
-  <ms fontsize="8179em">
-    <span xmlns="http://www.w3.org/1999/xhtml">
-      <span>
-        <td>
-          <mfrac xmlns="http://www.w3.org/1998/Math/MathML">
-            <mfrac>
-              <mrow/>
-              <mrow/>
-            </mfrac>
-            <mrow/>
-          </mfrac>
-        </td>
-      </span>
-    </span>
-  </ms>
-</math>
-
-</body>
-</html>
diff --git a/layout/style/crashtests/crashtests.list b/layout/style/crashtests/crashtests.list
index 3e7d1e2669..d54f053f1b 100644
--- a/layout/style/crashtests/crashtests.list
+++ b/layout/style/crashtests/crashtests.list
@@ -16,11 +16,8 @@ load 391034-1.xhtml
 load 397022-1.html
 load 399289-1.svg
 load 404470-1.html
-load 411603-1.html
 load 412588-1.html
-load 413274-1.xhtml
 skip-if(Android) load chrome://reftest/content/crashtests/layout/style/crashtests/416461-1.xhtml
-load 418007-1.xhtml
 load chrome://reftest/content/crashtests/layout/style/crashtests/431705-1.xhtml
 load 432561-1.html
 load 437170-1.html
@@ -229,7 +226,6 @@ load 1384232.html
 load 1395725.html
 load 1396041.html
 pref(dom.animations-api.compositing.enabled,true) load 1397363-1.html
-load 1397439-1.html
 load 1395719.html
 load 1397091.html
 load 1398479.html
@@ -251,7 +247,6 @@ load 1402419.html
 load 1402472.html
 load 1403028.html
 load 1403433.html
-load 1403465.html
 load 1403592.html
 load 1403615.html
 load 1403712.html
diff --git a/layout/style/nsCSSAnonBoxList.h b/layout/style/nsCSSAnonBoxList.h
index 891b34814b..4d62f5bd79 100644
--- a/layout/style/nsCSSAnonBoxList.h
+++ b/layout/style/nsCSSAnonBoxList.h
@@ -99,7 +99,6 @@ CSS_ANON_BOX(buttonContent, ":-moz-button-content")
 CSS_ANON_BOX(cellContent, ":-moz-cell-content")
 CSS_ANON_BOX(dropDownList, ":-moz-dropdown-list")
 CSS_ANON_BOX(fieldsetContent, ":-moz-fieldset-content")
-CSS_ANON_BOX(mozDisplayComboboxControlFrame, ":-moz-display-comboboxcontrol-frame")
 CSS_ANON_BOX(htmlCanvasContent, ":-moz-html-canvas-content")
 
 CSS_WRAPPER_ANON_BOX(inlineTable, ":-moz-inline-table")
diff --git a/layout/style/nsComputedDOMStyle.cpp b/layout/style/nsComputedDOMStyle.cpp
index 3b25ff9726..d40d4bc801 100644
--- a/layout/style/nsComputedDOMStyle.cpp
+++ b/layout/style/nsComputedDOMStyle.cpp
@@ -733,6 +733,16 @@ static void CollectImageURLsForProperty(nsCSSPropertyID aProp,
   }
 }
 
+float nsComputedDOMStyle::UsedFontSize() {
+  UpdateCurrentStyleSources(eCSSProperty_font_size);
+
+  if (!mComputedStyle) {
+    return -1.0;
+  }
+
+  return mComputedStyle->StyleFont()->mFont.size.ToCSSPixels();
+}
+
 void nsComputedDOMStyle::GetCSSImageURLs(const nsACString& aPropertyName,
                                          nsTArray<nsCString>& aImageURLs,
                                          mozilla::ErrorResult& aRv) {
@@ -990,6 +1000,19 @@ bool nsComputedDOMStyle::NeedsToFlushLayout(nsCSSPropertyID aPropID) const {
   }
 }
 
+bool nsComputedDOMStyle::NeedsToFlushLayoutForContainerQuery() const {
+  const auto* outerFrame = GetOuterFrame();
+  if (!outerFrame) {
+    return false;
+  }
+  const auto* innerFrame = nsLayoutUtils::GetStyleFrame(outerFrame);
+  MOZ_ASSERT(innerFrame, "No valid inner frame?");
+  // It's possible that potential containers are styled but not yet reflowed,
+  // i.e. They don't have a correct size, which makes any container query
+  // evaluation against them invalid.
+  return innerFrame->HasUnreflowedContainerQueryAncestor();
+}
+
 void nsComputedDOMStyle::Flush(Document& aDocument, FlushType aFlushType) {
   MOZ_ASSERT(mElement->IsInComposedDoc());
   MOZ_ASSERT(mDocumentWeak == &aDocument);
@@ -1051,8 +1074,9 @@ void nsComputedDOMStyle::UpdateCurrentStyleSources(nsCSSPropertyID aPropID) {
     Flush(*document, FlushType::Frames);
   }
 
-  if (NeedsToFlushLayout(aPropID)) {
-    MOZ_ASSERT(MayNeedToFlushLayout(aPropID));
+  const bool needsToFlushLayoutForProp = NeedsToFlushLayout(aPropID);
+  if (needsToFlushLayoutForProp || NeedsToFlushLayoutForContainerQuery()) {
+    MOZ_ASSERT_IF(needsToFlushLayoutForProp, MayNeedToFlushLayout(aPropID));
     didFlush = true;
     Flush(*document, FlushType::Layout);
 #ifdef DEBUG
diff --git a/layout/style/nsComputedDOMStyle.h b/layout/style/nsComputedDOMStyle.h
index 4a6fec785d..4f135a3aca 100644
--- a/layout/style/nsComputedDOMStyle.h
+++ b/layout/style/nsComputedDOMStyle.h
@@ -120,6 +120,8 @@ class nsComputedDOMStyle final : public nsDOMCSSDeclaration,
     mExposeVisitedStyle = aExpose;
   }
 
+  float UsedFontSize() final;
+
   void GetCSSImageURLs(const nsACString& aPropertyName,
                        nsTArray<nsCString>& aImageURLs,
                        mozilla::ErrorResult& aRv) final;
@@ -312,6 +314,10 @@ class nsComputedDOMStyle final : public nsDOMCSSDeclaration,
   // Find out if we need to flush layout of the document, depending on the
   // property that was requested.
   bool NeedsToFlushLayout(nsCSSPropertyID) const;
+  // Find out if we need to flush layout of the document due to container
+  // query being made before relevant query containers are reflowed at least
+  // once.
+  bool NeedsToFlushLayoutForContainerQuery() const;
   // Flushes the given document, which must be our document, and potentially the
   // mElement's document.
   void Flush(Document&, mozilla::FlushType);
diff --git a/layout/style/nsICSSDeclaration.h b/layout/style/nsICSSDeclaration.h
index 1750fd75c3..53dcbed4ec 100644
--- a/layout/style/nsICSSDeclaration.h
+++ b/layout/style/nsICSSDeclaration.h
@@ -86,6 +86,11 @@ class nsICSSDeclaration : public nsISupports, public nsWrapperCache {
     aRv.Throw(NS_ERROR_NOT_IMPLEMENTED);
   }
 
+  // [Chrome only]
+  // Used font-size (taking account of the min-font-size prefs), if available;
+  // returns -1.0 on failure to retrieve a value.
+  virtual float UsedFontSize() { return -1.0; }
+
   // WebIDL interface for CSSStyleDeclaration
   virtual void SetCssText(const nsACString& aString,
                           nsIPrincipal* aSubjectPrincipal,
diff --git a/layout/style/nsMediaFeatures.cpp b/layout/style/nsMediaFeatures.cpp
index c99eecb486..f888c127d4 100644
--- a/layout/style/nsMediaFeatures.cpp
+++ b/layout/style/nsMediaFeatures.cpp
@@ -248,6 +248,9 @@ bool Gecko_MediaFeatures_MatchesPlatform(StylePlatform aPlatform) {
 #elif defined(XP_MACOSX)
     case StylePlatform::Macos:
       return true;
+#elif defined(XP_IOS)
+    case StylePlatform::Ios:
+      return true;
 #else
 #  error "Unknown platform?"
 #endif
diff --git a/layout/style/nsStyleStruct.cpp b/layout/style/nsStyleStruct.cpp
index 123a1b3304..39f5b1a760 100644
--- a/layout/style/nsStyleStruct.cpp
+++ b/layout/style/nsStyleStruct.cpp
@@ -2020,7 +2020,7 @@ StyleTransition::StyleTransition(const StyleTransition& aCopy) = default;
 bool StyleTransition::operator==(const StyleTransition& aOther) const {
   return mTimingFunction == aOther.mTimingFunction &&
          mDuration == aOther.mDuration && mDelay == aOther.mDelay &&
-         mProperty == aOther.mProperty;
+         mProperty == aOther.mProperty && mBehavior == aOther.mBehavior;
 }
 
 StyleAnimation::StyleAnimation(const StyleAnimation& aCopy) = default;
@@ -3079,6 +3079,7 @@ nsStyleUIReset::nsStyleUIReset()
       mTransitionDurationCount(1),
       mTransitionDelayCount(1),
       mTransitionPropertyCount(1),
+      mTransitionBehaviorCount(1),
       mAnimations(
           nsStyleAutoArray<StyleAnimation>::WITH_SINGLE_INITIAL_ELEMENT),
       mAnimationTimingFunctionCount(1),
@@ -3120,6 +3121,7 @@ nsStyleUIReset::nsStyleUIReset(const nsStyleUIReset& aSource)
       mTransitionDurationCount(aSource.mTransitionDurationCount),
       mTransitionDelayCount(aSource.mTransitionDelayCount),
       mTransitionPropertyCount(aSource.mTransitionPropertyCount),
+      mTransitionBehaviorCount(aSource.mTransitionBehaviorCount),
       mAnimations(aSource.mAnimations.Clone()),
       mAnimationTimingFunctionCount(aSource.mAnimationTimingFunctionCount),
       mAnimationDurationCount(aSource.mAnimationDurationCount),
@@ -3178,6 +3180,7 @@ nsChangeHint nsStyleUIReset::CalcDifference(
        mTransitionDurationCount != aNewData.mTransitionDurationCount ||
        mTransitionDelayCount != aNewData.mTransitionDelayCount ||
        mTransitionPropertyCount != aNewData.mTransitionPropertyCount ||
+       mTransitionBehaviorCount != aNewData.mTransitionBehaviorCount ||
        mAnimations != aNewData.mAnimations ||
        mAnimationTimingFunctionCount !=
            aNewData.mAnimationTimingFunctionCount ||
@@ -3461,12 +3464,6 @@ void StyleCalcNode::ScaleLengthsBy(float aScale) {
   }
 }
 
-nscoord StyleCalcLengthPercentage::Resolve(nscoord aBasis,
-                                           CoordRounder aRounder) const {
-  CSSCoord result = ResolveToCSSPixels(CSSPixel::FromAppUnits(aBasis));
-  return aRounder(result * AppUnitsPerCSSPixel());
-}
-
 bool nsStyleDisplay::PrecludesSizeContainmentOrContentVisibilityWithFrame(
     const nsIFrame& aFrame) const {
   // The spec says that in the case of SVG, the contain property only applies
diff --git a/layout/style/nsStyleStruct.h b/layout/style/nsStyleStruct.h
index b2d68a5976..8835934eaf 100644
--- a/layout/style/nsStyleStruct.h
+++ b/layout/style/nsStyleStruct.h
@@ -1120,6 +1120,7 @@ struct StyleTransition {
   const StyleTime& GetDelay() const { return mDelay; }
   const StyleTime& GetDuration() const { return mDuration; }
   const StyleTransitionProperty& GetProperty() const { return mProperty; }
+  StyleTransitionBehavior GetBehavior() const { return mBehavior; }
 
   bool operator==(const StyleTransition& aOther) const;
   bool operator!=(const StyleTransition& aOther) const {
@@ -1133,6 +1134,7 @@ struct StyleTransition {
   StyleTime mDelay{0.0};
   StyleTransitionProperty mProperty{StyleTransitionProperty::NonCustom(
       StyleNonCustomPropertyId{uint16_t(eCSSProperty_all)})};
+  StyleTransitionBehavior mBehavior = StyleTransitionBehavior::Normal;
 };
 
 struct StyleAnimation {
@@ -1647,6 +1649,10 @@ struct MOZ_NEEDS_MEMMOVABLE_MEMBERS nsStyleUIReset {
     return mTransitions[aIndex % mTransitionTimingFunctionCount]
         .GetTimingFunction();
   }
+  mozilla::StyleTransitionBehavior GetTransitionBehavior(
+      uint32_t aIndex) const {
+    return mTransitions[aIndex % mTransitionBehaviorCount].GetBehavior();
+  }
   mozilla::StyleTime GetTransitionCombinedDuration(uint32_t aIndex) const {
     // https://drafts.csswg.org/css-transitions/#transition-combined-duration
     return {std::max(GetTransitionDuration(aIndex).seconds, 0.0f) +
@@ -1708,6 +1714,7 @@ struct MOZ_NEEDS_MEMMOVABLE_MEMBERS nsStyleUIReset {
   uint32_t mTransitionDurationCount;
   uint32_t mTransitionDelayCount;
   uint32_t mTransitionPropertyCount;
+  uint32_t mTransitionBehaviorCount;
   nsStyleAutoArray<mozilla::StyleAnimation> mAnimations;
   // The number of elements in mAnimations that are not from repeating
   // a list due to another property being longer.
diff --git a/layout/style/nsStyleTransformMatrix.cpp b/layout/style/nsStyleTransformMatrix.cpp
index 593bcbb39d..71f8f826c2 100644
--- a/layout/style/nsStyleTransformMatrix.cpp
+++ b/layout/style/nsStyleTransformMatrix.cpp
@@ -101,7 +101,8 @@ static nsRect GetSVGBox(const nsIFrame* aFrame) {
       // FIXME: Bug 1849054. We may have to update
       // SVGGeometryFrame::GetBBoxContribution() to get tighter stroke bounds.
       nsRect strokeBox = nsLayoutUtils::ComputeSVGReferenceRect(
-          const_cast<nsIFrame*>(aFrame), StyleGeometryBox::StrokeBox);
+          const_cast<nsIFrame*>(aFrame), StyleGeometryBox::StrokeBox,
+          nsLayoutUtils::MayHaveNonScalingStrokeCyclicDependency::Yes);
       // The |nsIFrame::mRect| includes markers, so we have to compute the
       // offsets without markers.
       return nsRect{strokeBox.x - aFrame->GetPosition().x,
diff --git a/layout/style/nsTransitionManager.cpp b/layout/style/nsTransitionManager.cpp
index ad3809c37f..66f1004354 100644
--- a/layout/style/nsTransitionManager.cpp
+++ b/layout/style/nsTransitionManager.cpp
@@ -116,6 +116,7 @@ bool nsTransitionManager::DoUpdateTransitions(
       continue;
     }
 
+    const auto behavior = aStyle.GetTransitionBehavior(i);
     ExpandTransitionProperty(aStyle.GetTransitionProperty(i),
                              [&](const AnimatedPropertyID& aProperty) {
                                // We might have something to transition.  See if
@@ -123,8 +124,9 @@ bool nsTransitionManager::DoUpdateTransitions(
                                // are animatable.
                                startedAny |= ConsiderInitiatingTransition(
                                    aProperty, aStyle, i, delay, duration,
-                                   aElement, aPseudoType, aElementTransitions,
-                                   aOldStyle, aNewStyle, propertiesChecked);
+                                   behavior, aElement, aPseudoType,
+                                   aElementTransitions, aOldStyle, aNewStyle,
+                                   propertiesChecked);
                              });
   }
 
@@ -248,8 +250,8 @@ GetReplacedTransitionProperties(const CSSTransition* aTransition,
 bool nsTransitionManager::ConsiderInitiatingTransition(
     const AnimatedPropertyID& aProperty, const nsStyleUIReset& aStyle,
     uint32_t aTransitionIndex, float aDelay, float aDuration,
-    dom::Element* aElement, PseudoStyleType aPseudoType,
-    CSSTransitionCollection*& aElementTransitions,
+    mozilla::StyleTransitionBehavior aBehavior, dom::Element* aElement,
+    PseudoStyleType aPseudoType, CSSTransitionCollection*& aElementTransitions,
     const ComputedStyle& aOldStyle, const ComputedStyle& aNewStyle,
     AnimatedPropertyIDSet& aPropertiesChecked) {
   // IsShorthand itself will assert if aProperty is not a property.
@@ -294,7 +296,7 @@ bool nsTransitionManager::ConsiderInitiatingTransition(
   AnimationValue startValue, endValue;
   const StyleShouldTransitionResult result =
       Servo_ComputedValues_ShouldTransition(
-          &aOldStyle, &aNewStyle, &property,
+          &aOldStyle, &aNewStyle, &property, aBehavior,
           oldTransition ? oldTransition->ToValue().mServo.get() : nullptr,
           &startValue.mServo, &endValue.mServo);
 
diff --git a/layout/style/nsTransitionManager.h b/layout/style/nsTransitionManager.h
index e87a0109a2..02a577690d 100644
--- a/layout/style/nsTransitionManager.h
+++ b/layout/style/nsTransitionManager.h
@@ -63,6 +63,7 @@ class nsTransitionManager final
   bool ConsiderInitiatingTransition(
       const mozilla::AnimatedPropertyID&, const nsStyleUIReset& aStyle,
       uint32_t aTransitionIndex, float aDelay, float aDuration,
+      mozilla::StyleTransitionBehavior aBehavior,
       mozilla::dom::Element* aElement, mozilla::PseudoStyleType aPseudoType,
       CSSTransitionCollection*& aElementTransitions,
       const mozilla::ComputedStyle& aOldStyle,
diff --git a/layout/style/res/forms.css b/layout/style/res/forms.css
index 9fb833aa74..a2d026639b 100644
--- a/layout/style/res/forms.css
+++ b/layout/style/res/forms.css
@@ -259,40 +259,27 @@ select:-moz-select-list-box {
 }
 
 select > button {
-  inline-size: 12px;
-  white-space: nowrap;
-  position: static;
+  padding: 0;
+  border: 0;
   appearance: auto;
   -moz-default-appearance: -moz-menulist-arrow-button;
 
-  /* Make sure to size correctly if the combobox has a non-auto height. */
-  block-size: 100%;
-  box-sizing: border-box;
-
   /* Draw the arrow in the select's color */
   color: inherit;
 
-  /*
-    Make sure to align properly with the display frame.  Note that we
-    want the baseline of the combobox to match the baseline of the
-    display frame, so the dropmarker is what gets the vertical-align.
-  */
+  /* We don't want the button to grow the line-height */
+  font: inherit;
+  max-block-size: 100%;
+
+  /* Make sure to align properly with the display frame.  Note that we want the
+   * baseline of the combobox to match the baseline of the label, so the
+   * dropmarker is what gets the vertical-align. */
   vertical-align: top;
 }
 
-*|*::-moz-display-comboboxcontrol-frame {
-  content: inherit;
+select > label {
+  display: inline-block;
   overflow: clip;
-  color: unset;
-  white-space: nowrap;
-  text-align: unset;
-  user-select: none;
-  /* Make sure to size correctly if the combobox has a non-auto block-size. */
-  block-size: 100%;
-  /* Try to always display our own text */
-  min-inline-size: max-content;
-  box-sizing: border-box;
-  line-height: -moz-block-height;
 }
 
 option[label]::before {
@@ -668,16 +655,15 @@ input[type=file] > label {
   *  inherit into the ':-moz-button-content' pseudo-element.
   *
   * <select>:
-  *  inherit into the ':-moz-display-comboboxcontrol-frame' pseudo-element and
-  *  the <optgroup>'s ':before' pseudo-element, which is where the label of
-  *  the <optgroup> gets displayed. The <option>s don't use anonymous boxes,
-  *  so they need no special rules.
+  *  inherit into the label and the <optgroup>'s ':before' pseudo-element,
+  *  which is where the label of the <optgroup> gets displayed. The <option>s
+  *  don't use anonymous boxes, so they need no special rules.
   */
 ::placeholder,
 ::-moz-text-control-editing-root,
 *|*::-moz-button-content,
-*|*::-moz-display-comboboxcontrol-frame,
-optgroup:before {
+select > label,
+optgroup::before {
   unicode-bidi: inherit;
   text-overflow: inherit;
 }
@@ -868,6 +854,13 @@ input[type=number]::-moz-number-spin-box {
   overflow: clip;
 }
 
+/* stylelint-disable-next-line media-query-no-invalid */
+@media (-moz-bool-pref: "dom.forms.number.hide_spin_buttons_when_no_hover_or_focus") {
+  input[type=number]:not(:hover, :focus)::-moz-number-spin-box {
+    opacity: 0;
+  }
+}
+
 input[type=number]::-moz-number-spin-up,
 input[type=number]::-moz-number-spin-down {
   writing-mode: horizontal-tb;
@@ -922,11 +915,7 @@ input:is([type=date], [type=time], [type=datetime-local]):is(:disabled, :read-on
 }
 
 input:autofill, select:autofill {
-  /* The idea behind using background-image instead of plain background-color
-   * is that it's less likely to be overridden by the page. */
-  background-image: linear-gradient(-moz-autofill-background, -moz-autofill-background);
-}
-
-input:-moz-autofill-preview, select:-moz-autofill-preview {
-  color: GrayText;
+  background-color: -moz-autofill-background !important;
+  background-image: none !important;
+  color: FieldText !important;
 }
diff --git a/layout/style/res/html.css b/layout/style/res/html.css
index 383aa35f7b..ff58ecd4d1 100644
--- a/layout/style/res/html.css
+++ b/layout/style/res/html.css
@@ -149,10 +149,8 @@ dd {
 
 blockquote, figure {
   display: block;
-  margin-block-start: 1em;
-  margin-block-end: 1em;
-  margin-inline-start: 40px;
-  margin-inline-end: 40px;
+  margin-block: 1em;
+  margin-inline: 40px;
 }
 
 address {
@@ -169,68 +167,85 @@ h1 {
   display: block;
   font-size: 2em;
   font-weight: bold;
-  margin-block-start: .67em;
-  margin-block-end: .67em;
+  margin-block: .67em;
 }
 
-h2,
-:is(article, aside, nav, section)
-h1 {
+h2 {
   display: block;
   font-size: 1.5em;
   font-weight: bold;
-  margin-block-start: .83em;
-  margin-block-end: .83em;
+  margin-block: .83em;
 }
 
-h3,
-:is(article, aside, nav, section)
-:is(article, aside, nav, section)
-h1 {
+h3 {
   display: block;
   font-size: 1.17em;
   font-weight: bold;
-  margin-block-start: 1em;
-  margin-block-end: 1em;
+  margin-block: 1em;
 }
 
-h4,
-:is(article, aside, nav, section)
-:is(article, aside, nav, section)
-:is(article, aside, nav, section)
-h1 {
+h4 {
   display: block;
   font-size: 1.00em;
   font-weight: bold;
-  margin-block-start: 1.33em;
-  margin-block-end: 1.33em;
+  margin-block: 1.33em;
 }
 
-h5,
-:is(article, aside, nav, section)
-:is(article, aside, nav, section)
-:is(article, aside, nav, section)
-:is(article, aside, nav, section)
-h1 {
+h5 {
   display: block;
   font-size: 0.83em;
   font-weight: bold;
-  margin-block-start: 1.67em;
-  margin-block-end: 1.67em;
+  margin-block: 1.67em;
 }
 
-h6,
-:is(article, aside, nav, section)
-:is(article, aside, nav, section)
-:is(article, aside, nav, section)
-:is(article, aside, nav, section)
-:is(article, aside, nav, section)
-h1 {
+h6 {
   display: block;
   font-size: 0.67em;
   font-weight: bold;
-  margin-block-start: 2.33em;
-  margin-block-end: 2.33em;
+  margin-block: 2.33em;
+}
+
+/* stylelint-disable-next-line media-query-no-invalid */
+@media (-moz-bool-pref: "layout.css.h1-in-section-ua-styles.enabled") {
+  :is(article, aside, nav, section)
+  h1 {
+    margin-block: 0.83em;
+    font-size: 1.50em;
+  }
+
+  :is(article, aside, nav, section)
+  :is(article, aside, nav, section)
+  h1 {
+    margin-block: 1.00em;
+    font-size: 1.17em;
+  }
+
+  :is(article, aside, nav, section)
+  :is(article, aside, nav, section)
+  :is(article, aside, nav, section)
+  h1 {
+    margin-block: 1.33em;
+    font-size: 1.00em;
+  }
+
+  :is(article, aside, nav, section)
+  :is(article, aside, nav, section)
+  :is(article, aside, nav, section)
+  :is(article, aside, nav, section)
+  h1 {
+    margin-block: 1.67em;
+    font-size: 0.83em;
+  }
+
+  :is(article, aside, nav, section)
+  :is(article, aside, nav, section)
+  :is(article, aside, nav, section)
+  :is(article, aside, nav, section)
+  :is(article, aside, nav, section)
+  h1 {
+    margin-block: 2.33em;
+    font-size: 0.67em;
+  }
 }
 
 listing {
@@ -238,16 +253,14 @@ listing {
   font-family: -moz-fixed;
   font-size: medium;
   white-space: pre;
-  margin-block-start: 1em;
-  margin-block-end: 1em;
+  margin-block: 1em;
 }
 
 xmp, pre, plaintext {
   display: block;
   font-family: -moz-fixed;
   white-space: pre;
-  margin-block-start: 1em;
-  margin-block-end: 1em;
+  margin-block: 1em;
 }
 
 /* tables */
@@ -380,25 +393,19 @@ table[rules][rules="cols"] > tr > td,
 table[rules][rules="cols"] > * > tr > td,
 table[rules][rules="cols"] > tr > th,
 table[rules][rules="cols"] > * > tr > th {
-  border-inline-start-width: thin;
-  border-inline-end-width: thin;
-  border-inline-start-style: solid;
-  border-inline-end-style: solid;
+  border-inline-width: thin;
+  border-inline-style: solid;
 }
 
 table[rules][rules="groups"] > colgroup {
-  border-inline-start-width: thin;
-  border-inline-end-width: thin;
-  border-inline-start-style: solid;
-  border-inline-end-style: solid;
+  border-inline-width: thin;
+  border-inline-style: solid;
 }
 table[rules][rules="groups"] > tfoot,
 table[rules][rules="groups"] > thead,
 table[rules][rules="groups"] > tbody {
-  border-block-start-width: thin;
-  border-block-end-width: thin;
-  border-block-start-style: solid;
-  border-block-end-style: solid;
+  border-block-width: thin;
+  border-block-style: solid;
 }
 
 
@@ -409,8 +416,7 @@ caption {
 }
 
 table[align="center"] > caption {
-  margin-inline-start: auto;
-  margin-inline-end: auto;
+  margin-inline: auto;
 }
 
 table[align="center"] > caption[align="left"]:dir(ltr) {
@@ -589,8 +595,7 @@ li {
 :is(ul, ol, dir, menu, dl) dir,
 :is(ul, ol, dir, menu, dl) menu,
 :is(ul, ol, dir, menu, dl) dl {
-  margin-block-start: 0;
-  margin-block-end: 0;
+  margin-block: 0;
 }
 
 /* 2 deep unordered lists use a circle */
@@ -618,10 +623,8 @@ hr {
   color: gray;
   border-width: 1px;
   border-style: inset;
-  margin-block-start: 0.5em;
-  margin-block-end: 0.5em;
-  margin-inline-start: auto;
-  margin-inline-end: auto;
+  margin-block: 0.5em;
+  margin-inline: auto;
   overflow: hidden;
 
   /* FIXME: This is not really per spec */
diff --git a/layout/style/test/ParseCSS.cpp b/layout/style/test/ParseCSS.cpp
index 04e37d48e2..e201d191a9 100644
--- a/layout/style/test/ParseCSS.cpp
+++ b/layout/style/test/ParseCSS.cpp
@@ -18,7 +18,6 @@
 #include "nsIFile.h"
 #include "nsNetUtil.h"
 
-#include "nsContentCID.h"
 #include "mozilla/StyleSheetInlines.h"
 #include "mozilla/css/Loader.h"
 
diff --git a/layout/style/test/animation_utils.js b/layout/style/test/animation_utils.js
index 6f7ededcd4..7239885e7c 100644
--- a/layout/style/test/animation_utils.js
+++ b/layout/style/test/animation_utils.js
@@ -4,6 +4,8 @@
 //
 //----------------------------------------------------------------------
 
+/* eslint-disable mozilla/no-comparison-or-assignment-inside-ok */
+
 function advance_clock(milliseconds) {
   SpecialPowers.DOMWindowUtils.advanceTimeAndRefresh(milliseconds);
 }
diff --git a/layout/style/test/chrome/bug418986-2.js b/layout/style/test/chrome/bug418986-2.js
index 6d2af235c3..c945eecca0 100644
--- a/layout/style/test/chrome/bug418986-2.js
+++ b/layout/style/test/chrome/bug418986-2.js
@@ -1,5 +1,7 @@
 // # Bug 418986, part 2.
 
+/* eslint-disable mozilla/no-comparison-or-assignment-inside-ok */
+
 const is_chrome_window = window.location.protocol === "chrome:";
 
 const HTML_NS = "http://www.w3.org/1999/xhtml";
diff --git a/layout/style/test/mochitest.toml b/layout/style/test/mochitest.toml
index 9df86ea539..54ad9736f2 100644
--- a/layout/style/test/mochitest.toml
+++ b/layout/style/test/mochitest.toml
@@ -18,6 +18,7 @@ prefs = [
   "layout.css.basic-shape-rect.enabled=true",
   "layout.css.basic-shape-xywh.enabled=true",
   "layout.css.transform-box-content-stroke.enabled=true",
+  "layout.css.transition-behavior.enabled=true",
 ]
 support-files = [
   "animation_utils.js",
diff --git a/layout/style/test/property_database.js b/layout/style/test/property_database.js
index 422f2ffe5c..2e8b4c71a3 100644
--- a/layout/style/test/property_database.js
+++ b/layout/style/test/property_database.js
@@ -13604,36 +13604,32 @@ if (IsCSSPropertyPrefEnabled("layout.css.backdrop-filter.enabled")) {
   };
 }
 
-if (IsCSSPropertyPrefEnabled("layout.css.math-depth.enabled")) {
-  gCSSProperties["math-depth"] = {
-    domProp: "mathDepth",
-    inherited: true,
-    type: CSS_TYPE_LONGHAND,
-    initial_values: ["0"],
-    other_values: [
-      // auto-add cannot be tested here because it has no effect when the
-      // inherited math-style is equal to the default (normal).
-      "123",
-      "-123",
-      "add(123)",
-      "add(-123)",
-      "calc(1 + 2*3)",
-      "add(calc(4 - 2/3))",
-    ],
-    invalid_values: ["auto", "1,23", "1.23", "add(1,23)", "add(1.23)"],
-  };
-}
+gCSSProperties["math-depth"] = {
+  domProp: "mathDepth",
+  inherited: true,
+  type: CSS_TYPE_LONGHAND,
+  initial_values: ["0"],
+  other_values: [
+    // auto-add cannot be tested here because it has no effect when the
+    // inherited math-style is equal to the default (normal).
+    "123",
+    "-123",
+    "add(123)",
+    "add(-123)",
+    "calc(1 + 2*3)",
+    "add(calc(4 - 2/3))",
+  ],
+  invalid_values: ["auto", "1,23", "1.23", "add(1,23)", "add(1.23)"],
+};
 
-if (IsCSSPropertyPrefEnabled("layout.css.math-style.enabled")) {
-  gCSSProperties["math-style"] = {
-    domProp: "mathStyle",
-    inherited: true,
-    type: CSS_TYPE_LONGHAND,
-    initial_values: ["normal"],
-    other_values: ["compact"],
-    invalid_values: [],
-  };
-}
+gCSSProperties["math-style"] = {
+  domProp: "mathStyle",
+  inherited: true,
+  type: CSS_TYPE_LONGHAND,
+  initial_values: ["normal"],
+  other_values: ["compact"],
+  invalid_values: [],
+};
 
 if (IsCSSPropertyPrefEnabled("layout.css.forced-color-adjust.enabled")) {
   gCSSProperties["forced-color-adjust"] = {
@@ -14088,6 +14084,36 @@ if (IsCSSPropertyPrefEnabled("layout.css.prefixes.transitions")) {
   });
 }
 
+if (IsCSSPropertyPrefEnabled("layout.css.transition-behavior.enabled")) {
+  Object.assign(gCSSProperties, {
+    "transition-behavior": {
+      domProp: "transitionBehavior",
+      inherited: false,
+      type: CSS_TYPE_LONGHAND,
+      applies_to_marker: true,
+      initial_values: ["normal"],
+      other_values: ["allow-discrete"],
+      invalid_values: ["none", "auto", "discrete"],
+    },
+  });
+
+  gCSSProperties["transition"].subproperties.push("transition-behavior");
+  gCSSProperties["transition"].initial_values.push("normal");
+  gCSSProperties["transition"].other_values.push(
+    "allow-discrete",
+    "width allow-discrete",
+    "1s allow-discrete",
+    "linear allow-discrete"
+  );
+  gCSSProperties["-webkit-transition"].subproperties.push(
+    "transition-behavior"
+  );
+
+  if (IsCSSPropertyPrefEnabled("layout.css.prefixes.transitions")) {
+    gCSSProperties["-moz-transition"].subproperties.push("transition-behavior");
+  }
+}
+
 // Copy aliased properties' fields from their alias targets. Keep this logic
 // at the bottom of this file to ensure all the aliased properties are
 // processed.
diff --git a/layout/style/test/test_shorthand_property_getters.html b/layout/style/test/test_shorthand_property_getters.html
index cade526183..b5db9519a6 100644
--- a/layout/style/test/test_shorthand_property_getters.html
+++ b/layout/style/test/test_shorthand_property_getters.html
@@ -183,17 +183,19 @@ e.setAttribute("style", "background-position-x: 0px; background-position-y: top
 is(e.style.backgroundPosition, "left 0px top 0px", "should serialize to 4-value form if 3-value form would only have one edge");
 
 // Check that we only serialize transition when the lists are the same length.
-e.setAttribute("style", "transition-property: color, width; transition-duration: 1s, 200ms; transition-timing-function: ease-in, linear; transition-delay: 0s, 1s");
+e.setAttribute("style", "transition-property: color, width; transition-duration: 1s, 200ms; transition-timing-function: ease-in, linear; transition-delay: 0s, 1s; transition-behavior: normal, allow-discrete;");
 isnot(e.style.transition, "", "should have transition shorthand (lists same length)");
-e.setAttribute("style", "transition-property: color, width, left; transition-duration: 1s, 200ms; transition-timing-function: ease-in, linear; transition-delay: 0s, 1s");
+e.setAttribute("style", "transition-property: color, width, left; transition-duration: 1s, 200ms; transition-timing-function: ease-in, linear; transition-delay: 0s, 1s; transition-behavior: normal, allow-discrete;");
 is(e.style.transition, "", "should not have transition shorthand (lists different lengths)");
-e.setAttribute("style", "transition-property: all; transition-duration: 1s, 200ms; transition-timing-function: ease-in, linear; transition-delay: 0s, 1s");
+e.setAttribute("style", "transition-property: all; transition-duration: 1s, 200ms; transition-timing-function: ease-in, linear; transition-delay: 0s, 1s; transition-behavior: normal, allow-discrete;");
 is(e.style.transition, "", "should not have transition shorthand (lists different lengths)");
-e.setAttribute("style", "transition-property: color, width; transition-duration: 1s, 200ms, 300ms; transition-timing-function: ease-in, linear; transition-delay: 0s, 1s");
+e.setAttribute("style", "transition-property: color, width; transition-duration: 1s, 200ms, 300ms; transition-timing-function: ease-in, linear; transition-delay: 0s, 1s; transition-behavior: normal, allow-discrete;");
 is(e.style.transition, "", "should not have transition shorthand (lists different lengths)");
-e.setAttribute("style", "transition-property: color, width; transition-duration: 1s, 200ms; transition-timing-function: ease-in, linear, ease-out; transition-delay: 0s, 1s");
+e.setAttribute("style", "transition-property: color, width; transition-duration: 1s, 200ms; transition-timing-function: ease-in, linear, ease-out; transition-delay: 0s, 1s; transition-behavior: normal, allow-discrete;");
 is(e.style.transition, "", "should not have transition shorthand (lists different lengths)");
-e.setAttribute("style", "transition-property: color, width; transition-duration: 1s, 200ms; transition-timing-function: ease-in, linear; transition-delay: 0s, 1s, 0s");
+e.setAttribute("style", "transition-property: color, width; transition-duration: 1s, 200ms; transition-timing-function: ease-in, linear; transition-delay: 0s, 1s, 0s; transition-behavior: normal, allow-discrete;");
+is(e.style.transition, "", "should not have transition shorthand (lists different lengths)");
+e.setAttribute("style", "transition-property: color, width; transition-duration: 1s, 200ms; transition-timing-function: ease-in, linear; transition-delay: 0s, 1s; transition-behavior: normal, allow-discrete, normal;");
 is(e.style.transition, "", "should not have transition shorthand (lists different lengths)");
 e.setAttribute("style", "transition: color, width; transition-delay: 0s");
 is(e.style.transition, "", "should not have transition shorthand (lists different lengths)");
author	Daniel Baumann <daniel.baumann@progress-linux.org>	2024-04-19 01:14:29 +0000
committer	Daniel Baumann <daniel.baumann@progress-linux.org>	2024-04-19 01:14:29 +0000
commit	fbaf0bb26397aa498eb9156f06d5a6fe34dd7dd8 (patch)
tree	4c1ccaf5486d4f2009f9a338a98a83e886e29c97 /layout/style
parent	Releasing progress-linux version 124.0.1-1~progress7.99u1. (diff)
download	firefox-fbaf0bb26397aa498eb9156f06d5a6fe34dd7dd8.tar.xz firefox-fbaf0bb26397aa498eb9156f06d5a6fe34dd7dd8.zip