diff --git a/layout/generic/nsLineBox.cpp b/layout/generic/nsLineBox.cpp
index 1ac406866603..03da8aa026ff 100644
--- a/layout/generic/nsLineBox.cpp
+++ b/layout/generic/nsLineBox.cpp
@@ -192,17 +192,19 @@ ListFloats(FILE* out, const char* aPrefix, const nsFloatCacheList& aFloats)
   }
 }
 
-const char *
-BreakTypeToString(uint8_t aBreakType)
+const char*
+nsLineBox::BreakTypeToString(uint8_t aBreakType) const
 {
   switch (aBreakType) {
-  case NS_STYLE_CLEAR_NONE: return "nobr";
-  case NS_STYLE_CLEAR_LEFT: return "leftbr";
-  case NS_STYLE_CLEAR_RIGHT: return "rightbr";
-  case NS_STYLE_CLEAR_BOTH: return "leftbr+rightbr";
-  case NS_STYLE_CLEAR_LINE: return "linebr";
-  default:
-    break;
+    case NS_STYLE_CLEAR_NONE: return "nobr";
+    case NS_STYLE_CLEAR_LEFT: return "leftbr";
+    case NS_STYLE_CLEAR_RIGHT: return "rightbr";
+    case NS_STYLE_CLEAR_INLINE_START: return "inlinestartbr";
+    case NS_STYLE_CLEAR_INLINE_END: return "inlineendbr";
+    case NS_STYLE_CLEAR_BOTH: return "leftbr+rightbr";
+    case NS_STYLE_CLEAR_LINE: return "linebr";
+    default:
+      break;
   }
   return "unknown";
 }
diff --git a/layout/generic/nsLineBox.h b/layout/generic/nsLineBox.h
index f0f645315338..095a62fb613d 100644
--- a/layout/generic/nsLineBox.h
+++ b/layout/generic/nsLineBox.h
@@ -572,6 +572,7 @@ public:
                                     int32_t* aFrameIndexInLine);
 
 #ifdef DEBUG_FRAME_DUMP
+  const char* BreakTypeToString(uint8_t aBreakType) const;
   char* StateToString(char* aBuf, int32_t aBufSize) const;
 
   void List(FILE* out, int32_t aIndent, uint32_t aFlags = 0) const;