Remove an extra relayout for non-percent logical height grid items

Source/core/rendering/RenderGrid.cpp

 /*
  * Copyright (C) 2011 Apple 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:
  * 1. Redistributions of source code must retain the above copyright
  *    notice, this list of conditions and the following disclaimer.
  * 2. Redistributions in binary form must reproduce the above copyright
  *    notice, this list of conditions and the following disclaimer in the
@@ skipping 852 matching lines @@
         // the grid breadth to account for 'box-sizing'.
         LayoutUnit oldOverrideContainingBlockContentLogicalWidth = child->hasOverrideContainingBlockLogicalWidth() ? child->overrideContainingBlockContentLogicalWidth() : LayoutUnit();
         LayoutUnit oldOverrideContainingBlockContentLogicalHeight = child->hasOverrideContainingBlockLogicalHeight() ? child->overrideContainingBlockContentLogicalHeight() : LayoutUnit();
 
         // FIXME: For children in a content sized track, we clear the overrideContainingBlockContentLogicalHeight
         // in minContentForChild / maxContentForChild which means that we will always relayout the child.
         LayoutUnit overrideContainingBlockContentLogicalWidth = gridAreaBreadthForChild(child, ForColumns, columnTracks);
         LayoutUnit overrideContainingBlockContentLogicalHeight = gridAreaBreadthForChild(child, ForRows, rowTracks);
 
         SubtreeLayoutScope layoutScope(child);
-        if (oldOverrideContainingBlockContentLogicalWidth != overrideContainingBlockContentLogicalWidth || oldOverrideContainingBlockContentLogicalHeight != overrideContainingBlockContentLogicalHeight)
+        if (oldOverrideContainingBlockContentLogicalWidth != overrideContainingBlockContentLogicalWidth || (child->hasRelativeLogicalHeight() && oldOverrideContainingBlockContentLogicalHeight != overrideContainingBlockContentLogicalHeight))

[Julien - ping for review, 2013/09/11 00:06:05]

I went ahead and switched to RenderBox::hasRelativeLogicalHeight. Ojan, WDYT?

             layoutScope.setNeedsLayout(child);
 
         child->setOverrideContainingBlockContentLogicalWidth(overrideContainingBlockContentLogicalWidth);
         child->setOverrideContainingBlockContentLogicalHeight(overrideContainingBlockContentLogicalHeight);
 
         LayoutRect oldChildRect = child->frameRect();
 
         // FIXME: Grid items should stretch to fill their cells. Once we
         // implement grid-{column,row}-align, we can also shrink to fit. For
         // now, just size as if we were a regular child.
@@ skipping 268 matching lines @@
     if (isOutOfFlowPositioned())
         return "RenderGrid (positioned)";
     if (isAnonymous())
         return "RenderGrid (generated)";
     if (isRelPositioned())
         return "RenderGrid (relative positioned)";
     return "RenderGrid";
 }
 
 } // namespace WebCore