Remove V8ArrayBufferViewCustomScript.js

Looks like it's unused.

Review URL: https://codereview.chromium.org/127303002

git-svn-id: svn://svn.chromium.org/blink/trunk@164669 bbb929c8-8fbe-4397-9dbb-9b2b20218538
Remove Document::idAttributeName.

This abstraction isn't pulling its weight: Many callers (including in
SVG, Inspector, editing and DOM) use HTMLNames::idAttr directly. Blink
doesn't support XML Schema, etc. that might make this ever return
anything other than HTMLNames::idAttr, so let's just use idAttr
directly everywhere.

Nor does it make sense to store a constant idAttr in each Document
instance.

BUG=none

Review URL: https://codereview.chromium.org/127393002

git-svn-id: svn://svn.chromium.org/blink/trunk@164670 bbb929c8-8fbe-4397-9dbb-9b2b20218538