Fix under-invalidation about view background change caused by body style change

Source/core/layout/LayoutView.cpp

Index: Source/core/layout/LayoutView.cpp
diff --git a/Source/core/layout/LayoutView.cpp b/Source/core/layout/LayoutView.cpp
index fffada0c13ab05cc26371a2d1efbde84fd4cff6d..9f0597e9386c289687b26edfa7de1add33a9a9a6 100644
--- a/Source/core/layout/LayoutView.cpp
+++ b/Source/core/layout/LayoutView.cpp
@@ -165,14 +165,14 @@ bool LayoutView::shouldDoFullPaintInvalidationForNextLayout() const
         return true;
 
     if (size().height() != viewHeight()) {
-        if (LayoutObject* backgroundRenderer = this->backgroundRenderer()) {
+        if (LayoutObject* backgroundLayoutObject = this->backgroundLayoutObject()) {
             // When background-attachment is 'fixed', we treat the viewport (instead of the 'root'
             // i.e. html or body) as the background positioning area, and we should full paint invalidation
             // viewport resize if the background image is not composited and needs full paint invalidation on
             // background positioning area resize.
             if (!m_compositor || !m_compositor->needsFixedRootBackgroundLayer(layer())) {
-                if (backgroundRenderer->style()->hasFixedBackgroundImage()
-                    && mustInvalidateFillLayersPaintOnHeightChange(backgroundRenderer->style()->backgroundLayers()))
+                if (backgroundLayoutObject->style()->hasFixedBackgroundImage()
+                    && mustInvalidateFillLayersPaintOnHeightChange(backgroundLayoutObject->style()->backgroundLayers()))
                     return true;
             }
         }
@@ -812,12 +812,12 @@ IntRect LayoutView::unscaledDocumentRect() const
 
 bool LayoutView::rootBackgroundIsEntirelyFixed() const
 {
-    if (LayoutObject* backgroundRenderer = this->backgroundRenderer())
-        return backgroundRenderer->hasEntirelyFixedBackground();
+    if (LayoutObject* backgroundLayoutObject = this->backgroundLayoutObject())
+        return backgroundLayoutObject->hasEntirelyFixedBackground();
     return false;
 }
 
-LayoutObject* LayoutView::backgroundRenderer() const
+LayoutObject* LayoutView::backgroundLayoutObject() const
 {
     if (Element* documentElement = document().documentElement()) {
         if (LayoutObject* rootObject = documentElement->layoutObject())
@@ -826,7 +826,7 @@ LayoutObject* LayoutView::backgroundRenderer() const
     return 0;
 }
 
-LayoutRect LayoutView::backgroundRect(LayoutBox* backgroundRenderer) const
+LayoutRect LayoutView::backgroundRect(LayoutBox* backgroundLayoutObject) const
 {
     if (!hasColumns())
         return LayoutRect(unscaledDocumentRect());
@@ -835,7 +835,7 @@ LayoutRect LayoutView::backgroundRect(LayoutBox* backgroundRenderer) const
     LayoutRect backgroundRect(0, 0, columnInfo->desiredColumnWidth(), columnInfo->columnHeight() * columnInfo->columnCount());
     if (!isHorizontalWritingMode())
         backgroundRect = backgroundRect.transposedRect();
-    backgroundRenderer->flipForWritingMode(backgroundRect);
+    backgroundLayoutObject->flipForWritingMode(backgroundRect);
 
     return backgroundRect;
 }