Backing out fix for bug 223737, since it causes severe performance problems

when typing at the beginning of long text in a textarea (and in general can
cause us to reflow a lot more lines than we should have to).  a=roc

layout/generic/nsBlockFrame.cpp

@@ -4084,11 +4084,13 @@ nsBlockFrame::ReflowInlineFrame(nsBlockReflowState& aState,
         return rv;
       }
 
-      // Mark next line dirty, since a line followed by a <BR>
-      // needs to continue to reflow.
-      nsLineList_iterator next = aLine.next();
-      if (next != end_lines() && !next->IsBlock()) {
-        next->MarkDirty();
+      if (NS_FRAME_IS_NOT_COMPLETE(frameReflowStatus)) {
+        // Mark next line dirty in case SplitLine didn't end up
+        // pushing any frames.
+        nsLineList_iterator next = aLine.next();
+        if (next != end_lines() && !next->IsBlock()) {
+          next->MarkDirty();
+        }
       }
     }
   }