#50998

r=rods, a/sr=buster
OS/2 has support for GetAveCharWidth so enable it

layout/generic/nsTextFrame.cpp

@@ -494,7 +494,7 @@ public:
       aRenderingContext.SetFont(mNormalFont);
       aRenderingContext.GetWidth(' ', mSpaceWidth);
       mAveCharWidth = 0;
-#ifdef _WIN32
+#if defined(_WIN32) || defined(XP_OS2)
       mNormalFont->GetAveCharWidth(mAveCharWidth);
 #endif
       if (0 == mAveCharWidth) {

layout/html/base/src/nsTextFrame.cpp

@@ -494,7 +494,7 @@ public:
       aRenderingContext.SetFont(mNormalFont);
       aRenderingContext.GetWidth(' ', mSpaceWidth);
       mAveCharWidth = 0;
-#ifdef _WIN32
+#if defined(_WIN32) || defined(XP_OS2)
       mNormalFont->GetAveCharWidth(mAveCharWidth);
 #endif
       if (0 == mAveCharWidth) {

layout/html/forms/src/nsGfxTextControlFrame2.cpp

@@ -1364,7 +1364,7 @@ nsGfxTextControlFrame2::CalculateSizeStandard (nsIPresContext*       aPresContex
   // nsIFontMetrics. The other need to have it implemeneted (Bug 50998)
   // and then this if def removed. We are too close to RTM to implement it in all 
   // the platforms and ports.
-#ifdef _WIN32
+#if defined(_WIN32) || defined(XP_OS2)
   fontMet->GetAveCharWidth(charWidth);
 #else
   // XP implementation of AveCharWidth