To reproduce:

1. Download attached project "blend-shapes.zip" and open in Unity
2. Open "SampleScene" scene
3. Make sure the current target is Standalone or iOS
4. Make sure GPU Skinning is enabled in PlayerSettings
5. Open Unity Profiler
6. Enter to Play Mode
7. Record a few frames, then Pause/Stop PlayMode
8. In the CPU Profiler, click on a frame
9. Switch to Timeline view

Expected results: MeshSkinning.Skin marker should not be visible
Actual results: MeshSkinning.Skin appears on Mac

Notes:
- This issue only appears on Metal Graphics API
- The Correct behavior would be if You see on Profiler MeshSkinning.SkinOnGPU
- The Project and Profiler results are attached in the Comments section
- The Fix in a Trunk that landed a week ago so it need to be Backported: 37e9fa1abaf6 and 6ba8ab588991

Reproduced on Unity 2017.4.0f1, 2017.4.23f1, 2018.3.8f1 and 2019.1.0b6
Could not reproduce on Unity 2019.2.0a7