IDL compiler: [DependentLifetime] interfaces

V. simple one.

Doc:
https://sites.google.com/a/chromium.org/dev/blink/webidl/blink-idl-extended-attributes#TOC-DependentLifetime-i-

BUG=239771
NOTRY=true

Review URL: https://codereview.chromium.org/80283002

git-svn-id: svn://svn.chromium.org/blink/trunk@162444 bbb929c8-8fbe-4397-9dbb-9b2b20218538
IDL compiler: [DoNotCheckConstants]

Test-only change, as extended attribute supported when initially implemented
constants.

BUG=239771
NOTRY=true
TBR=haraken

Review URL: https://codereview.chromium.org/80303002

git-svn-id: svn://svn.chromium.org/blink/trunk@162445 bbb929c8-8fbe-4397-9dbb-9b2b20218538