diff --git a/mozilla/layout/forms/nsComboboxControlFrame.cpp b/mozilla/layout/forms/nsComboboxControlFrame.cpp
index c88dd51ec2d..6c928db8724 100644
--- a/mozilla/layout/forms/nsComboboxControlFrame.cpp
+++ b/mozilla/layout/forms/nsComboboxControlFrame.cpp
@@ -624,30 +624,6 @@ nsComboboxControlFrame::GetDropdownFrame()
 }
 
 
-nsresult 
-nsComboboxControlFrame::GetScreenHeight(nsIPresContext* aPresContext,
-                                        nscoord& aHeight)
-{
-  aHeight = 0;
-  nsIDeviceContext* context;
-  aPresContext->GetDeviceContext( &context );
-	if ( nsnull != context )
-	{
-		PRInt32 height;
-    PRInt32 width;
-		context->GetDeviceSurfaceDimensions(width, height);
-		float devUnits;
- 		context->GetDevUnitsToAppUnits(devUnits);
-		aHeight = NSToIntRound(float( height) / devUnits );
-		NS_RELEASE( context );
-		return NS_OK;
-	}
-
-  return NS_ERROR_FAILURE;
-}
-
-int counter = 0;
-
 nsresult 
 nsComboboxControlFrame::PositionDropdown(nsIPresContext* aPresContext, 
                                          nscoord aHeight, 
@@ -676,7 +652,7 @@ nsComboboxControlFrame::PositionDropdown(nsIPresContext* aPresContext,
   dropdownFrame->GetRect(dropdownRect);
 
   nscoord screenHeightInPixels = 0;
-  if (NS_SUCCEEDED(GetScreenHeight(aPresContext, screenHeightInPixels))) {
+  if (NS_SUCCEEDED(nsFormControlFrame::GetScreenHeight(aPresContext, screenHeightInPixels))) {
      // Get the height of the dropdown list in pixels.
      float t2p;
      aPresContext->GetTwipsToPixels(&t2p);
diff --git a/mozilla/layout/forms/nsComboboxControlFrame.h b/mozilla/layout/forms/nsComboboxControlFrame.h
index 69f4edfc955..22e92eaf37f 100644
--- a/mozilla/layout/forms/nsComboboxControlFrame.h
+++ b/mozilla/layout/forms/nsComboboxControlFrame.h
@@ -200,7 +200,6 @@ protected:
                             nscoord                  aAvailableWidth,
                             nscoord                  aAvailableHeight);
 
-  nsresult GetScreenHeight(nsIPresContext* aPresContext, nscoord& aHeight);
 public:
   nsresult PositionDropdown(nsIPresContext* aPresContext,
                             nscoord aHeight, 
diff --git a/mozilla/layout/html/forms/src/nsComboboxControlFrame.cpp b/mozilla/layout/html/forms/src/nsComboboxControlFrame.cpp
index c88dd51ec2d..6c928db8724 100644
--- a/mozilla/layout/html/forms/src/nsComboboxControlFrame.cpp
+++ b/mozilla/layout/html/forms/src/nsComboboxControlFrame.cpp
@@ -624,30 +624,6 @@ nsComboboxControlFrame::GetDropdownFrame()
 }
 
 
-nsresult 
-nsComboboxControlFrame::GetScreenHeight(nsIPresContext* aPresContext,
-                                        nscoord& aHeight)
-{
-  aHeight = 0;
-  nsIDeviceContext* context;
-  aPresContext->GetDeviceContext( &context );
-	if ( nsnull != context )
-	{
-		PRInt32 height;
-    PRInt32 width;
-		context->GetDeviceSurfaceDimensions(width, height);
-		float devUnits;
- 		context->GetDevUnitsToAppUnits(devUnits);
-		aHeight = NSToIntRound(float( height) / devUnits );
-		NS_RELEASE( context );
-		return NS_OK;
-	}
-
-  return NS_ERROR_FAILURE;
-}
-
-int counter = 0;
-
 nsresult 
 nsComboboxControlFrame::PositionDropdown(nsIPresContext* aPresContext, 
                                          nscoord aHeight, 
@@ -676,7 +652,7 @@ nsComboboxControlFrame::PositionDropdown(nsIPresContext* aPresContext,
   dropdownFrame->GetRect(dropdownRect);
 
   nscoord screenHeightInPixels = 0;
-  if (NS_SUCCEEDED(GetScreenHeight(aPresContext, screenHeightInPixels))) {
+  if (NS_SUCCEEDED(nsFormControlFrame::GetScreenHeight(aPresContext, screenHeightInPixels))) {
      // Get the height of the dropdown list in pixels.
      float t2p;
      aPresContext->GetTwipsToPixels(&t2p);
diff --git a/mozilla/layout/html/forms/src/nsComboboxControlFrame.h b/mozilla/layout/html/forms/src/nsComboboxControlFrame.h
index 69f4edfc955..22e92eaf37f 100644
--- a/mozilla/layout/html/forms/src/nsComboboxControlFrame.h
+++ b/mozilla/layout/html/forms/src/nsComboboxControlFrame.h
@@ -200,7 +200,6 @@ protected:
                             nscoord                  aAvailableWidth,
                             nscoord                  aAvailableHeight);
 
-  nsresult GetScreenHeight(nsIPresContext* aPresContext, nscoord& aHeight);
 public:
   nsresult PositionDropdown(nsIPresContext* aPresContext,
                             nscoord aHeight,