Does a thesis have to have a "Discussion" chapter?
Do you discuss the results and their implications?  Do you present the insights and conclusions?  Do you make your argument and present your evidence in a logical, persuasive way? 

I find that chapter/section headings are much less important than the overall document strength. If your thesis fits the following, the I'd defend it.  Worst case you may be asked to restructure; best case you make your point and it is accepted as is. 

Key Points: 
Thesis should 
- be organized and logical
- clearly articulate the main points and supporting evidence
- discuss any conclusions and insights

I'm sure there are others.  Section/chapter headings are author's choice - use what you need to accomplish your purpose.