Forward font collection APIs to the SkParagraph font collection (flutter#21734)

Author: jason-simmons

third_party/txt/src/txt/font_collection.cc

@@ -85,6 +85,12 @@ FontCollection::FontCollection() : enable_font_fallback_(true) {}
 
 FontCollection::~FontCollection() {
   minikin::Layout::purgeCaches();
+
+#if FLUTTER_ENABLE_SKSHAPER
+  if (skt_collection_) {
+    skt_collection_->clearCaches();
+  }
+#endif
 }
 
 size_t FontCollection::GetFontManagersCount() const {
@@ -127,6 +133,12 @@ std::vector<sk_sp<SkFontMgr>> FontCollection::GetFontManagerOrder() const {
 
 void FontCollection::DisableFontFallback() {
   enable_font_fallback_ = false;
+
+#if FLUTTER_ENABLE_SKSHAPER
+  if (skt_collection_) {
+    skt_collection_->disableFontFallback();
+  }
+#endif
 }
 
 std::shared_ptr<minikin::FontCollection>
@@ -346,8 +358,13 @@ FontCollection::GetFallbackFontFamily(const sk_sp<SkFontMgr>& manager,
 
 void FontCollection::ClearFontFamilyCache() {
   font_collections_cache_.clear();
-}
 
+#if FLUTTER_ENABLE_SKSHAPER
+  if (skt_collection_) {
+    skt_collection_->clearCaches();
+  }
+#endif
+}
 #if FLUTTER_ENABLE_SKSHAPER
 
 sk_sp<skia::textlayout::FontCollection>