Use correct active stylesheets for collecting user fonts.

If there were no @font-face rules in the document, but @font-face rules
in user origin stylesheets, we would collect fonts based on the previous
set of active user sheets. Pass the correct new active sheets.

Bug: 1157821
Change-Id: I19a4578b5cced1568516e586208e37066c7df873
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2584926Reviewed-by: Xiaocheng Hu <xiaochengh@chromium.org>
Commit-Queue: Rune Lillesveen <futhark@chromium.org>
Cr-Commit-Position: refs/heads/master@{#836642}

third_party/blink/renderer/core/css/style_engine.cc

@@ -688,7 +688,8 @@ void StyleEngine::DidDetach() {
   environment_variables_ = nullptr;
 }
 
-bool StyleEngine::ClearFontFaceCacheAndAddUserFonts() {
+bool StyleEngine::ClearFontFaceCacheAndAddUserFonts(
+    const ActiveStyleSheetVector& user_sheets) {
   bool fonts_changed = false;
 
   if (font_selector_ &&
@@ -699,9 +700,9 @@ bool StyleEngine::ClearFontFaceCacheAndAddUserFonts() {
   }
 
   // Rebuild the font cache with @font-face rules from user style sheets.
-  for (unsigned i = 0; i < active_user_style_sheets_.size(); ++i) {
-    DCHECK(active_user_style_sheets_[i].second);
-    if (AddUserFontFaceRules(*active_user_style_sheets_[i].second))
+  for (unsigned i = 0; i < user_sheets.size(); ++i) {
+    DCHECK(user_sheets[i].second);
+    if (AddUserFontFaceRules(*user_sheets[i].second))
       fonts_changed = true;
   }
 
@@ -1541,7 +1542,8 @@ void StyleEngine::ApplyUserRuleSetChanges(
       scoped_resolver->SetNeedsAppendAllSheets();
       MarkDocumentDirty();
     } else {
-      has_rebuilt_font_face_cache = ClearFontFaceCacheAndAddUserFonts();
+      has_rebuilt_font_face_cache =
+          ClearFontFaceCacheAndAddUserFonts(new_style_sheets);
     }
   }
 
@@ -1662,8 +1664,10 @@ void StyleEngine::ApplyRuleSetChanges(
   }
 
   bool has_rebuilt_font_face_cache = false;
-  if (rebuild_font_face_cache)
-    has_rebuilt_font_face_cache = ClearFontFaceCacheAndAddUserFonts();
+  if (rebuild_font_face_cache) {
+    has_rebuilt_font_face_cache =
+        ClearFontFaceCacheAndAddUserFonts(active_user_style_sheets_);
+  }
 
   unsigned append_start_index = 0;
   if (scoped_resolver) {

third_party/blink/renderer/core/css/style_engine.h

@@ -515,7 +515,8 @@ class CORE_EXPORT StyleEngine final : public GarbageCollected<StyleEngine>,
   void UpdateStyleSheetList(TreeScope&);
 
   // Returns true if any @font-face rules are added or removed.
-  bool ClearFontFaceCacheAndAddUserFonts();
+  bool ClearFontFaceCacheAndAddUserFonts(
+      const ActiveStyleSheetVector& user_sheets);
 
   void ClearKeyframeRules() { keyframes_rule_map_.clear(); }
   void ClearPropertyRules();

third_party/blink/renderer/core/css/style_engine_test.cc

@@ -652,6 +652,29 @@ TEST_F(StyleEngineTest, AnalyzedInject) {
       t11->GetComputedStyle()->VisitedDependentColor(GetCSSPropertyColor()));
 }
 
+TEST_F(StyleEngineTest, InjectedUserNoAuthorFontFace) {
+  UpdateAllLifecyclePhases();
+
+  FontDescription font_description;
+  FontFaceCache* cache = GetStyleEngine().GetFontSelector()->GetFontFaceCache();
+  EXPECT_FALSE(cache->Get(font_description, "User"));
+
+  auto* user_sheet = MakeGarbageCollected<StyleSheetContents>(
+      MakeGarbageCollected<CSSParserContext>(GetDocument()));
+  user_sheet->ParseString(
+      "@font-face {"
+      "  font-family: 'User';"
+      "  src: url(font.ttf);"
+      "}");
+
+  StyleSheetKey user_key("user");
+  GetStyleEngine().InjectSheet(user_key, user_sheet, WebDocument::kUserOrigin);
+
+  UpdateAllLifecyclePhases();
+
+  EXPECT_TRUE(cache->Get(font_description, "User"));
+}
+
 TEST_F(StyleEngineTest, InjectedFontFace) {
   GetDocument().body()->setInnerHTML(R"HTML(
     <style>