Updated docs.

include/bgfx/bgfx.h

@@ -641,8 +641,9 @@ namespace bgfx
 		uint64_t gpuTimeEnd;   //!< GPU frame end time.
 		uint64_t gpuTimerFreq; //!< GPU timer frequency.
 
-		int64_t waitRender;    //!< Render wait time.
-		int64_t waitSubmit;    //!< Submit wait time.
+		int64_t waitRender;    //!< Time spent waiting for render backend thread to finish issuing
+		                       //!  draw commands to underlying graphics API.
+		int64_t waitSubmit;    //!< Time spent waiting for submit thread to advance to next frame.
 	};
 
 	/// Vertex declaration.