Are you asking about 'Concurrency Visualizer' under 'Analyze' menu in VS 2012? The tool will detect contention as long as there is blocking happening (that is, thread being blocked waiting for lock, etc), because it's based on kernel scheduler ETW events, which will occur whenever an thread blocks. Blocking shows up as red in the UI.
Now, a lot of these locks including SRW will often spin for a while before waiting, in case of contention; and often times the lock can be acquired after spinning without need to block (exactly the intention of spinning). In this case, since there is no block, the tool then cannot know that spinning (very short contention) occurred.
Hope this answers your question.