The current WIP version of code hotness visualizer (Bug 146115) is tightly coupled with code coverage profiler, it modifies BasicBlockAnnotator.js. It should be possible to turn code hotness visualizer (yellow-orange background and execution counts next to the line gutter) on and off without affecting code coverage profiler (grayed out unexecuted text), as the former will be off by default and the latter will be on.
<rdar://problem/23700951>