[Profiler] Profiler window does not show data after loading saved samples

To reproduce:
1. Create a new project.
2. Open Profiler Window
3. Enter Playmode, profile some data and exit Playmode.
4. Save samples from Profiler.
5. Clear Profiler window data.
6. Load sample file to Profiler.

Expected results: All frames are shown in Profiler window.

Actual result: Samples graphs are not shown in Profiler window, but you can select each frame and see data in the detailed view.

Regression (see screenshot attached):
Reproduces since
Version 2018.3.0a1 (d734fac073ec)
Wed, 06 Jun 2018 08:19:04 GMT
Branch: trunk

Does not reproduce in
Version 2018.2.0f2 (787658998520)
Thu, 05 Jul 2018 21:08:42 GMT
Branch: 2018.2/staging