Bug 1621415 - Ensure adopted styles are applied when printing r=emilio

- Add functionality to clone adopted style sheets for printing.
- Add reftest to ensure that the document's adopted styles show in print.
- Add reftest to ensure that a shadow root's adopted styles show in print.

Differential Revision: https://phabricator.services.mozilla.com/D66517

--HG--
extra : moz-landing-system : lando

dom/base/Document.cpp

@@ -12076,6 +12076,7 @@ already_AddRefed<Document> Document::CreateStaticClone(
           }
         }
       }
+      clonedDoc->CloneAdoptedSheetsFrom(*this);
 
       for (int t = 0; t < AdditionalSheetTypeCount; ++t) {
         auto& sheets = mAdditionalSheets[additionalSheetType(t)];

dom/base/DocumentOrShadowRoot.cpp

@@ -198,6 +198,27 @@ void DocumentOrShadowRoot::ClearAdoptedStyleSheets() {
   mAdoptedStyleSheets.Clear();
 }
 
+void DocumentOrShadowRoot::CloneAdoptedSheetsFrom(
+    DocumentOrShadowRoot& aSource) {
+  Document& ownerDoc = *AsNode().OwnerDoc();
+  Sequence<OwningNonNull<StyleSheet>> list;
+  if (!list.SetCapacity(mAdoptedStyleSheets.Length(), fallible)) {
+    return;
+  }
+
+  // TODO(nordzilla, bug 1621415) We can improve the performance here.
+  // https://bugzilla.mozilla.org/show_bug.cgi?id=1622322
+  for (auto& sheet : aSource.mAdoptedStyleSheets) {
+    DebugOnly<bool> succeeded =
+        list.AppendElement(sheet->CloneAdoptedSheet(ownerDoc), fallible);
+    MOZ_ASSERT(succeeded);
+  }
+
+  ErrorResult rv;
+  SetAdoptedStyleSheets(list, rv);
+  MOZ_ASSERT(!rv.Failed());
+}
+
 Element* DocumentOrShadowRoot::GetElementById(const nsAString& aElementId) {
   if (MOZ_UNLIKELY(aElementId.IsEmpty())) {
     nsContentUtils::ReportEmptyGetElementByIdArg(AsNode().OwnerDoc());

dom/base/DocumentOrShadowRoot.h

@@ -245,6 +245,12 @@ class DocumentOrShadowRoot {
   void RemoveSheetFromStylesIfApplicable(StyleSheet&);
   void ClearAdoptedStyleSheets();
 
+  /**
+   * Clone's the argument's adopted style sheets into this.
+   * This should only be used when cloning a static document for printing.
+   */
+  void CloneAdoptedSheetsFrom(DocumentOrShadowRoot&);
+
   // Returns the reference to the sheet, if found in mStyleSheets.
   already_AddRefed<StyleSheet> RemoveSheet(StyleSheet& aSheet);
   void InsertSheetAt(size_t aIndex, StyleSheet& aSheet);

dom/base/ShadowRoot.cpp

@@ -107,6 +107,7 @@ void ShadowRoot::CloneInternalDataFrom(ShadowRoot* aOther) {
       }
     }
   }
+  CloneAdoptedSheetsFrom(*aOther);
 }
 
 nsresult ShadowRoot::Bind() {

layout/base/tests/chrome/chrome.ini

@@ -1,5 +1,6 @@
 [DEFAULT]
 prefs =
+  layout.css.constructable-stylesheets.enabled=true
   layout.css.individual-transform.enabled=true
   layout.css.motion-path.enabled=true
   plugin.load_flash_only=false
@@ -21,6 +22,10 @@ support-files =
   printpreview_font_mozprintcallback_ref.html
   printpreview_quirks.html
   printpreview_quirks_ref.html
+  test_document_adopted_styles.html
+  test_document_adopted_styles_ref.html
+  test_shadow_root_adopted_styles.html
+  test_shadow_root_adopted_styles_ref.html
   file_bug1018265.xhtml
 
 [test_bug396367-1.html]

layout/base/tests/chrome/printpreview_helper.xhtml

@@ -31,7 +31,7 @@ function printpreview(hasMozPrintCallback) {
   gWbp = frameElts[1].docShell.initOrReusePrintPreviewViewer();
   var listener = {
     onLocationChange: function(webProgress, request, location, flags) { },
-    onProgressChange: function(webProgress, request, curSelfProgress, 
+    onProgressChange: function(webProgress, request, curSelfProgress,
                                maxSelfProgress, curTotalProgress,
                                maxTotalProgress) { },
     onSecurityChange: function(webProgress, request, state) { },
@@ -100,10 +100,14 @@ function runTests()
 }
 
 function compareCanvases() {
-  return window.windowUtils
-               .compareCanvases(document.getElementsByTagName("canvas")[0],
-                                document.getElementsByTagName("canvas")[1],
-                                {}) == 0;
+  const canvas1 = document.getElementsByTagName("canvas")[0];
+  const canvas2 = document.getElementsByTagName("canvas")[1];
+  const result = window.windowUtils.compareCanvases(canvas1, canvas2, {}) == 0;
+  if (!result) {
+    todo(false, "TEST CASE: " + canvas1.toDataURL());
+    todo(false, "REFERENCE: " + canvas2.toDataURL());
+  }
+  return result;
 }
 
 function addHTMLContent(parent) {
@@ -422,8 +426,20 @@ async function runTest11() {
   requestAnimationFrame(function() { setTimeout(runTest12); } );
 }
 
-// Crash test for bug 1615261
+// bug 1621415
 async function runTest12() {
+  await compareFiles("test_document_adopted_styles.html", "test_document_adopted_styles_ref.html");
+  requestAnimationFrame(function() { setTimeout(runTest13); } );
+}
+
+// bug 1621415
+async function runTest13() {
+  await compareFiles("test_shadow_root_adopted_styles.html", "test_shadow_root_adopted_styles_ref.html");
+  requestAnimationFrame(function() { setTimeout(runTest14); } );
+}
+
+// Crash test for bug 1615261
+async function runTest14() {
   frameElts[0].contentDocument.body.innerHTML =
     '<style> div { width: 100px; height: 100px; background-image: url("animated.gif"); } </style>' +
     '<div>Firefox will crash if you try and print this page</div>';

layout/base/tests/chrome/test_document_adopted_styles.html

@@ -0,0 +1,8 @@
+<!doctype html>
+<meta charset="utf-8">
+<div class="target"></div>
+<script>
+  const sheet = new CSSStyleSheet();
+  document.adoptedStyleSheets = [sheet];
+  sheet.replaceSync(".target { width: 100px; height: 100px; border-style: solid; border-color: blue; }");
+</script>

layout/base/tests/chrome/test_document_adopted_styles_ref.html

@@ -0,0 +1,6 @@
+<!doctype html>
+<meta charset="utf-8">
+<body>
+  <div class="target"></div>
+  <style> .target { width: 100px; height: 100px; border-style: solid; border-color: blue; } </style>
+</body>

layout/base/tests/chrome/test_shadow_root_adopted_styles.html

@@ -0,0 +1,11 @@
+<!doctype html>
+<meta charset="utf-8">
+<body>
+<script>
+  document.body.attachShadow({mode: "open"}).innerHTML = `
+    <div class="target"></div>
+  `;
+  const sheet = new CSSStyleSheet();
+  document.body.shadowRoot.adoptedStyleSheets = [sheet];
+  sheet.replaceSync(".target { width: 100px; height: 100px; border-style: solid; border-color: blue; }");
+</script>

layout/base/tests/chrome/test_shadow_root_adopted_styles_ref.html

@@ -0,0 +1,11 @@
+<!doctype html>
+<meta charset="utf-8">
+<body>
+<script>
+  document.body.attachShadow({mode: "open"}).innerHTML = `
+    <div class="target"></div>
+    <style>
+      .target { width: 100px; height: 100px; border-style: solid; border-color: blue; }
+    </style>
+  `;
+</script>

layout/style/StyleSheet.cpp

@@ -1321,12 +1321,29 @@ already_AddRefed<StyleSheet> StyleSheet::Clone(
     StyleSheet* aCloneParent, dom::CSSImportRule* aCloneOwnerRule,
     dom::DocumentOrShadowRoot* aCloneDocumentOrShadowRoot,
     nsINode* aCloneOwningNode) const {
+  MOZ_ASSERT(!IsConstructed(),
+             "Cannot create a non-constructed sheet from a constructed sheet");
   RefPtr<StyleSheet> clone =
       new StyleSheet(*this, aCloneParent, aCloneOwnerRule,
                      aCloneDocumentOrShadowRoot, aCloneOwningNode);
   return clone.forget();
 }
 
+already_AddRefed<StyleSheet> StyleSheet::CloneAdoptedSheet(
+    Document& aConstructorDocument) const {
+  MOZ_ASSERT(IsConstructed(),
+             "Cannot create a constructed sheet from a non-constructed sheet");
+  MOZ_ASSERT(aConstructorDocument.IsStaticDocument(),
+             "Should never clone adopted sheets for a non-static document");
+  RefPtr<StyleSheet> clone = new StyleSheet(*this,
+                                            /* aParentToUse */ nullptr,
+                                            /* aOwnerRuleToUse */ nullptr,
+                                            /* aDocumentOrShadowRoot */ nullptr,
+                                            /* aOwningNodeToUse */ nullptr);
+  clone->mConstructorDocument = &aConstructorDocument;
+  return clone.forget();
+}
+
 ServoCSSRuleList* StyleSheet::GetCssRulesInternal() {
   if (!mRuleList) {
     EnsureUniqueInner();

layout/style/StyleSheet.h

@@ -221,6 +221,13 @@ class StyleSheet final : public nsICSSLoaderObserver, public nsWrapperCache {
       dom::DocumentOrShadowRoot* aCloneDocumentOrShadowRoot,
       nsINode* aCloneOwningNode) const;
 
+  /**
+   * Creates a clone of the adopted style sheet as though it were constructed
+   * by aConstructorDocument. This should only be used for printing.
+   */
+  already_AddRefed<StyleSheet> CloneAdoptedSheet(
+      dom::Document& aConstructorDocument) const;
+
   bool HasForcedUniqueInner() const {
     return bool(mState & State::ForcedUniqueInner);
   }