Consolidate constructormagic macros with Chromium version and remove Chromium override.

Part of work removing dependency on Chromium's base.

Only adds "= delete". From https://codereview.chromium.org/1151443003 :
"This will guarantee the error to be at compile time, and not rely on the call visibility (private)."

In consequence of that change, fixed an illegal copy and removed a bunch of unused variables.

BUG=chromium:468375 (in particular comment #37)
NOTRY=true

Review URL: https://codereview.webrtc.org/1316363005

Cr-Commit-Position: refs/heads/master@{#9913}
12 files changed