Logic's Flex Time and Ableton's Warping are conceptually similar, in that they're timestretching based on markers.
In Live, audio is stored in Audio Clips, and the Clip View editor will pop up if you double-click one. Warping is not done from the Arrangement View timeline - it's done within the clip itself.
If the Warp switch is engaged on the Sample pane in the lower-left of Clip View, you can create Warp Markers by doubleclicking in the timeline area, just below the ruler. You will see one marker created by default at the beginning of the clip. The way warping is controlled is by creating Warp Markers for each position you are interested in, and moving that warp marker to the correct position in musical time. So if your sample is 1.5 bars long, you position your markers so that it begins on the 1.1.1 point in the clip timeline, and ends on 3.1.1. The timeline within the clip is relative to the clip itself. However, once you know your clip is two bars long, it will be the correct length in the Arrangement view and you can position and loop it however you need.