Clear baseLayoutStyle when the font selector version has increased.

Source/platform/fonts/FontFallbackList.cpp

Index: Source/platform/fonts/FontFallbackList.cpp
diff --git a/Source/platform/fonts/FontFallbackList.cpp b/Source/platform/fonts/FontFallbackList.cpp
index e905ceeaed213016905e13c27bd9611b756a9b86..d4661e4fcea40c12e5ef35f53f946cbff64183e1 100644
--- a/Source/platform/fonts/FontFallbackList.cpp
+++ b/Source/platform/fonts/FontFallbackList.cpp
@@ -244,4 +244,12 @@ const FontData* FontFallbackList::fontDataAt(const FontDescription& fontDescript
     return result.get();
 }
 
+bool FontFallbackList::isValid() const
+{
+    if (!m_fontSelector)
+        return m_fontSelectorVersion == 0;
+
+    return m_fontSelector->version() == m_fontSelectorVersion;
+}
+
 } // namespace blink