Merge 139435

Source/WebCore/rendering/TextAutosizer.cpp

 /*
  * Copyright (C) 2012 Google Inc. All rights reserved.
  * Copyright (C) 2012 Apple Inc. All rights reserved.
  *
  * This library is free software; you can redistribute it and/or
  * modify it under the terms of the GNU Library General Public
  * License as published by the Free Software Foundation; either
  * version 2 of the License, or (at your option) any later version.
  *
  * This library is distributed in the hope that it will be useful,
@@ skipping 198 matching lines @@
     //
     // Clusters are chosen using very similar criteria to CSS flow roots, aka
     // block formatting contexts (http://w3.org/TR/css3-box/#flow-root), since
     // flow roots correspond to box containers that behave somewhat
     // independently from their parent (for example they don't overlap floats).
     // The definition of a flow root also conveniently includes most of the
     // ways that a box and its children can have significantly different width
     // from the box's parent (we want to avoid having significantly different
     // width blocks within a cluster, since the narrower blocks would end up
     // larger than would otherwise be necessary).
-    // Additionally, any containers that are wider than the |blockContainingAllText|
-    // of their enclosing cluster also become clusters, since they need special
-    // treatment due to their width.
+    // Additionally, any containers that are wider or at least 200px narrower than
+    // the |blockContainingAllText| of their enclosing cluster also become clusters,
+    // since they need special treatment due to their width.
     ASSERT(isAutosizingContainer(renderer));
 
+    // Upper limit on the difference between the width of the parent block containing all
+    // text and that of a narrow child before the child becomes a cluster.
+    const float maxWidthDifference = 200;
+
+    if (parentBlockContainingAllText) {
+        float contentWidth = renderer->contentLogicalWidth();
+        float clusterTextWidth = parentBlockContainingAllText->contentLogicalWidth();
+        if (contentWidth > clusterTextWidth || (clusterTextWidth - contentWidth) > maxWidthDifference)
+            return true;
+    }
+
     return renderer->isRenderView()
         || renderer->isFloating()
         || renderer->isOutOfFlowPositioned()
         || renderer->isTableCell()
         || renderer->isTableCaption()
         || renderer->isFlexibleBoxIncludingDeprecated()
         || renderer->hasColumns()
         || renderer->containingBlock()->isHorizontalWritingMode() != renderer->isHorizontalWritingMode()
-        || renderer->style()->isDisplayReplacedType()
-        || (parentBlockContainingAllText
-            && renderer->contentLogicalWidth() > parentBlockContainingAllText->contentLogicalWidth());
+        || renderer->style()->isDisplayReplacedType();
     // FIXME: Tables need special handling to multiply all their columns by
     // the same amount even if they're different widths; so do hasColumns()
     // containers, and probably flexboxes...
 }
 
 bool TextAutosizer::isAutosizingCluster(const RenderObject* object)
 {
     return isAutosizingContainer(object) && isAutosizingCluster(toRenderBlock(object), 0);
 }
 
@@ skipping 141 matching lines @@
         child = (direction == FirstToLast) ? child->nextSibling() : child->previousSibling();
     }
     --depth;
 
     return 0;
 }
 
 } // namespace WebCore
 
 #endif // ENABLE(TEXT_AUTOSIZING)