Revert of Enable the WebIDL [Exposed] annotation on an interface's members. (https://codereview.chromium.org/424163002/)

Reason for revert:
Causes interactive_ui_tests to timeout

Tests:
WebViewInteractiveTest.PopupPositioningBasic
WebViewInteractiveTest.PopupPositioningMoved

See: http://build.chromium.org/p/chromium.webkit/builders/Linux%20Tests/builds/38370/steps/interactive_ui_tests/logs/stdio

Original issue's description:
> Enable the WebIDL [Exposed] annotation on an interface's members.
> 
> Blink only supports [Exposed] as an interface-level annotation right now,
> but it also makes sense as a member-level annotation in case certain members
> should only be available in a subset of the interface's exposure set.
> 
> The first user for this will be the Web Notifications API, which now
> defines requestPermission() to only be exposed on Document, whereas the rest
> of the API will be available in both windows and workers.
> 
> BUG=398446
> 
> Committed: https://src.chromium.org/viewvc/blink?view=rev&revision=179418

TBR=haraken@chromium.org,jl@opera.com,ch.dumez@samsung.com,bashi@chromium.org,peter@chromium.org
NOTREECHECKS=true
NOTRY=true
BUG=398446

Review URL: https://codereview.chromium.org/426583003

git-svn-id: svn://svn.chromium.org/blink/trunk@179426 bbb929c8-8fbe-4397-9dbb-9b2b20218538