Updating didUpdateThisFrame property in LateUpdate() makes sense for MovieTexture because it's an output but WebCamTexture (which came later) needs to update before the Update() because it's an Input.
Steps to reproduce:
1. Open attached project
2. Build and run for android
3. Inspect the green and red +/- symbols (green symbol stands for Update() and red for lateUpdate())

Result: didUpdateThisFrame is set after the webCamTexture is rendered.
Expected result: didUpdateThisFrame should be set before the webCamTexture is rendered.

Reproduced with: 5.6.1p3, 2017.1.0f2, 2017.2.0b2

Devices under test:

Reproduced with:
Sony D6503, OS:6.0.1, CPU:armeabi-v7a, GPU:Adreno (TM) 330, Build:Sony/D6503/D6503:6.0.1/23.5.A.1.291/2769308465:user/release-keys
Xiaomi MI 5s, OS:6.0.1, CPU:arm64-v8a, GPU:Adreno (TM) 530, Build:Xiaomi/capricorn/capricorn:6.0.1/MXB48T/V8.0.10.0.MAGCNDH:user/release-keys