reflow was using the wrong DC to rendering context for PP

BUg 117745 r=dcone sr=attinasi

widget/src/mac/nsDeviceContextMac.cpp

@@ -126,7 +126,7 @@ NS_IMETHODIMP nsDeviceContextMac :: CreateRenderingContext(nsIRenderingContext *
 {
 #ifdef NS_PRINT_PREVIEW
   // Defer to Alt when there is one
-  if (mAltDC && (mUseAltDC & kUseAltDCFor_CREATE_RC)) {
+  if (mAltDC && ((mUseAltDC & kUseAltDCFor_CREATERC_PAINT) || (mUseAltDC & kUseAltDCFor_CREATERC_REFLOW))) {
     return mAltDC->CreateRenderingContext(aContext);
   }
 #endif