[New Multicolumn] Faster and more direct RenderMultiColumnSet::multiColumnFlowThread().

Source/core/rendering/RenderMultiColumnSet.cpp

Index: Source/core/rendering/RenderMultiColumnSet.cpp
diff --git a/Source/core/rendering/RenderMultiColumnSet.cpp b/Source/core/rendering/RenderMultiColumnSet.cpp
index e54c7a0fb38a6a2638aec6ef87eec4361eef7283..92f4c7c33dca8e3e2e007865984cef5bd485dbc1 100644
--- a/Source/core/rendering/RenderMultiColumnSet.cpp
+++ b/Source/core/rendering/RenderMultiColumnSet.cpp
@@ -251,7 +251,7 @@ void RenderMultiColumnSet::prepareForLayout()
     // Set box width.
     updateLogicalWidth();
 
-    if (multicolBlock->multiColumnFlowThread()->requiresBalancing()) {
+    if (multiColumnFlowThread()->requiresBalancing()) {
         // Set maximum column height. We will not stretch beyond this.
         m_maxColumnHeight = RenderFlowThread::maxLogicalHeight();
         if (!multicolStyle->logicalHeight().isAuto()) {
@@ -267,7 +267,7 @@ void RenderMultiColumnSet::prepareForLayout()
         m_maxColumnHeight = heightAdjustedForSetOffset(m_maxColumnHeight);
         m_computedColumnHeight = 0; // Restart balancing.
     } else {
-        setAndConstrainColumnHeight(heightAdjustedForSetOffset(multicolBlock->multiColumnFlowThread()->columnHeightAvailable()));
+        setAndConstrainColumnHeight(heightAdjustedForSetOffset(multiColumnFlowThread()->columnHeightAvailable()));
     }
 
     clearForcedBreaks();