diff --git a/layout/style/nsComputedDOMStyle.cpp b/layout/style/nsComputedDOMStyle.cpp
index 928847dd4e9..312a53601bd 100644
--- a/layout/style/nsComputedDOMStyle.cpp
+++ b/layout/style/nsComputedDOMStyle.cpp
@@ -100,6 +100,14 @@ NS_NewComputedDOMStyle(nsIComputedDOMStyle** aComputedStyle)
   return NS_OK;
 }
 
+static nsIFrame*
+GetContainingBlockFor(nsIFrame* aFrame) {
+  if (!aFrame) {
+    return nsnull;
+  }
+  return nsHTMLReflowState::GetContainingBlockFor(aFrame);
+}
+
 nsComputedDOMStyle::nsComputedDOMStyle()
   : mInner(this), mPresShellWeak(nsnull), mT2P(0.0f)
 {
@@ -1835,8 +1843,7 @@ nsComputedDOMStyle::GetTextIndent(nsIFrame *aFrame,
         break;
       case eStyleUnit_Percent:
         {
-          nsIFrame *container =
-            nsHTMLReflowState::GetContainingBlockFor(aFrame);
+          nsIFrame *container = GetContainingBlockFor(aFrame);
           if (container) {
             val->SetTwips(container->GetSize().width *
                           text->mTextIndent.GetPercentValue());
@@ -2715,7 +2722,7 @@ nsComputedDOMStyle::GetMaxHeight(nsIFrame *aFrame,
     nscoord minHeight = 0;
 
     if (positionData->mMinHeight.GetUnit() == eStyleUnit_Percent) {
-      container = nsHTMLReflowState::GetContainingBlockFor(aFrame);
+      container = GetContainingBlockFor(aFrame);
       if (container) {
         size = container->GetSize();
         minHeight = nscoord(size.height *
@@ -2732,7 +2739,7 @@ nsComputedDOMStyle::GetMaxHeight(nsIFrame *aFrame,
         break;
       case eStyleUnit_Percent:
         if (!container) {
-          container = nsHTMLReflowState::GetContainingBlockFor(aFrame);
+          container = GetContainingBlockFor(aFrame);
           if (container) {
             size = container->GetSize();
           } else {
@@ -2775,7 +2782,7 @@ nsComputedDOMStyle::GetMaxWidth(nsIFrame *aFrame,
     nscoord minWidth = 0;
 
     if (positionData->mMinWidth.GetUnit() == eStyleUnit_Percent) {
-      container = nsHTMLReflowState::GetContainingBlockFor(aFrame);
+      container = GetContainingBlockFor(aFrame);
       if (container) {
         size = container->GetSize();
         minWidth = nscoord(size.width *
@@ -2792,7 +2799,7 @@ nsComputedDOMStyle::GetMaxWidth(nsIFrame *aFrame,
         break;
       case eStyleUnit_Percent:
         if (!container) {
-          container = nsHTMLReflowState::GetContainingBlockFor(aFrame);
+          container = GetContainingBlockFor(aFrame);
           if (container) {
             size = container->GetSize();
           } else {
@@ -2836,7 +2843,7 @@ nsComputedDOMStyle::GetMinHeight(nsIFrame *aFrame,
         val->SetTwips(positionData->mMinHeight.GetCoordValue());
         break;
       case eStyleUnit_Percent:
-        container = nsHTMLReflowState::GetContainingBlockFor(aFrame);
+        container = GetContainingBlockFor(aFrame);
         if (container) {
           val->SetTwips(container->GetSize().height *
                         positionData->mMinHeight.GetPercentValue());
@@ -2876,7 +2883,7 @@ nsComputedDOMStyle::GetMinWidth(nsIFrame *aFrame,
         val->SetTwips(positionData->mMinWidth.GetCoordValue());
         break;
       case eStyleUnit_Percent:
-        container = nsHTMLReflowState::GetContainingBlockFor(aFrame);
+        container = GetContainingBlockFor(aFrame);
         if (container) {
           val->SetTwips(container->GetSize().width *
                         positionData->mMinWidth.GetPercentValue());
@@ -2970,7 +2977,7 @@ nsComputedDOMStyle::GetAbsoluteOffset(PRUint8 aSide, nsIFrame* aFrame,
   nsROCSSPrimitiveValue *val = GetROCSSPrimitiveValue();
   NS_ENSURE_TRUE(val, NS_ERROR_OUT_OF_MEMORY);
 
-  nsIFrame* container = nsHTMLReflowState::GetContainingBlockFor(aFrame);
+  nsIFrame* container = GetContainingBlockFor(aFrame);
   if (container) {
     nscoord margin = GetMarginWidthCoordFor(aSide, aFrame);
     nscoord border = GetBorderWidthCoordFor(aSide, container);
@@ -3059,7 +3066,7 @@ nsComputedDOMStyle::GetRelativeOffset(PRUint8 aSide, nsIFrame* aFrame,
         val->SetTwips(sign * coord.GetCoordValue());
         break;
       case eStyleUnit_Percent:
-        container = nsHTMLReflowState::GetContainingBlockFor(aFrame);
+        container = GetContainingBlockFor(aFrame);
         if (container) {
           nsMargin border;
           nsMargin padding;