Steps to repro:

1. Open attached project and 'bugMetalDeferred' scene on OSX (Metal);
2. Resize Game view tab;
3. Observe tree rendering.

Actual result:
Tree leaves are not rendered. Also trees are blinking in Scene view. See attached video and actual.png screenshot.
Regression introduced in Unity 5.6.

Expected result:
Trees should be rendered without artifacts. See attached expected.png screenshot.

Workaround is to set Forward rendering path on 'Main Camera' gameobject.

Notes:
- Reproducible in 5.6.0b7;
- Not reproducible in 5.5.0p4;
- Reproducible only on OSX Metal; not reproducible in OSX GlCore and Windows DX11 and Windows GlCore;
- Reproducible only in Deferred / not reproducible in Forward;
- Reproducible in both Editor and Standalone player for Metal.