Remove destructors from ScriptWrappable objects (part 2)

Now that ScriptWrappable doesn't need a destructor, we can change
GarbageCollectedFinalized to GarbageCollected.

BUG=340522

Review URL: https://codereview.chromium.org/363423002

git-svn-id: svn://svn.chromium.org/blink/trunk@177524 bbb929c8-8fbe-4397-9dbb-9b2b20218538