[FastTextAutosizer] Do not inflate blocks with no children

Source/core/rendering/FastTextAutosizer.cpp

 /*
  * Copyright (C) 2013 Google Inc. All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions are
  * met:
  *
  *     * Redistributions of source code must retain the above copyright
  * notice, this list of conditions and the following disclaimer.
  *     * Redistributions in binary form must reproduce the above
@@ skipping 118 matching lines @@
         // This can happen with paginated overflow.
         return;
     }
 
     if (Cluster* cluster = maybeCreateCluster(block)) {
         m_clusterStack.append(adoptPtr(cluster));
         if (block->isTable())
             inflateTable(toRenderTable(block));
     }
 
-    if (block->childrenInline())
+    if (block->childrenInline() && block->firstChild())
         inflate(block);
 }
 
 void FastTextAutosizer::inflateListItem(RenderListItem* listItem, RenderListMarker* listItemMarker)
 {
     if (!enabled())
         return;
     ASSERT(listItem && listItemMarker);
 #ifndef NDEBUG
     m_blocksThatHaveBegunLayout.add(listItem);
@@ skipping 41 matching lines @@
                 }
             }
         }
     }
 }
 
 void FastTextAutosizer::endLayout(RenderBlock* block)
 {
     ASSERT(enabled());
 
-    if (currentCluster()->m_root == block)
-        m_clusterStack.removeLast();
-
     if (block == m_firstBlock) {
         m_firstBlock = 0;
         m_clusterStack.clear();
         m_superclusters.clear();
 #ifndef NDEBUG
         m_blocksThatHaveBegunLayout.clear();
 #endif
+    } else if (currentCluster()->m_root == block) {
+        m_clusterStack.removeLast();
     }
 }
 
 void FastTextAutosizer::inflate(RenderBlock* block)
 {
     Cluster* cluster = currentCluster();
     float multiplier = 0;
     for (RenderObject* descendant = nextChildSkippingChildrenOfBlocks(block, block); descendant; descendant = nextChildSkippingChildrenOfBlocks(descendant, block)) {
         if (descendant->isText()) {
             // We only calculate this multiplier on-demand to ensure the parent block of this text
@@ skipping 476 matching lines @@
 }
 
 RenderObject* FastTextAutosizer::nextChildSkippingChildrenOfBlocks(const RenderObject* current, const RenderObject* stayWithin)
 {
     if (current == stayWithin || !current->isRenderBlock())
         return current->nextInPreOrder(stayWithin);
     return current->nextInPreOrderAfterChildren(stayWithin);
 }
 
 } // namespace WebCore