Merge 94508 - <rdar://problem/10071256> Retain retired custom fonts until the next style recalc

Source/WebCore/dom/Document.cpp

Index: Source/WebCore/dom/Document.cpp
===================================================================
--- Source/WebCore/dom/Document.cpp	(revision 95343)
+++ Source/WebCore/dom/Document.cpp	(working copy)
@@ -546,6 +546,8 @@
             (*m_pageGroupUserSheets)[i]->clearOwnerNode();
     }
 
+    deleteRetiredCustomFonts();
+
     m_weakReference->clear();
 
     if (m_mediaQueryMatcher)
@@ -1528,6 +1530,9 @@
         if (change >= Inherit || n->childNeedsStyleRecalc() || n->needsStyleRecalc())
             n->recalcStyle(change);
 
+    // Now that all RenderStyles that pointed to retired fonts have been updated, the fonts can safely be deleted.
+    deleteRetiredCustomFonts();
+
 #if USE(ACCELERATED_COMPOSITING)
     if (view()) {
         bool layoutPending = view()->layoutPending() || renderer()->needsLayout();
@@ -1664,6 +1669,20 @@
     return style.release();
 }
 
+void Document::retireCustomFont(FontData* fontData)
+{
+    m_retiredCustomFonts.append(adoptPtr(fontData));
+}
+
+void Document::deleteRetiredCustomFonts()
+{
+    size_t size = m_retiredCustomFonts.size();
+    for (size_t i = 0; i < size; ++i)
+        GlyphPageTreeNode::pruneTreeCustomFontData(m_retiredCustomFonts[i].get());
+
+    m_retiredCustomFonts.clear();
+}
+
 bool Document::isPageBoxVisible(int pageIndex)
 {
     RefPtr<RenderStyle> style = styleForPage(pageIndex);