Add invalidateLayout to RoomBubbleCellData.

Riot/Modules/Room/CellData/RoomBubbleCellData.h

@@ -95,6 +95,16 @@ typedef NS_ENUM(NSInteger, RoomBubbleCellDataTag)
  */
 @property(nonatomic) NSInteger componentIndexOfSentMessageTick;
 
+/**
+ Indicate that both the text message layout and any additional content height are no longer
+ valid and should be recomputed before presentation in a bubble cell. This could be due
+ to a content change, or the available space for the cell has been updated.
+ 
+ This is a convenience method that calls `invalidateTextLayout` and
+ `setNeedsUpdateAdditionalContentHeight` together.
+ */
+- (void)invalidateLayout;
+
 /**
  Indicate to update additional content height.
  */