Inject a prototype object of a private script into the prototype chain of a holder object

Inject a prototype object of a private script into the prototype chain of a holder object

This is a split CL from https://codereview.chromium.org/394773003/.

This CL lets |this| object use properties defined on a prototype object of the private script. For example:

installClass("HTMLMarqueeElement", function(global, HTMLMarqueeElementPrototype) {
  HTMLMarqueeElementPrototype.foo = function () { ... };
  HTMLMarqueeElementPrototype.bar = function () {
    this.foo();  // This CL makes this workable.
  };
});

Before this CL, we had to write foo.call(this) because the HTMLMarqueeElementPrototype is not in the prototype chain of |this| object. After this CL, the HTMLMarqueeElementPrototype is in the prototype chain, so we can just write it as this.foo().

BUG=341031
TEST=fast/dom/private_script_unittest.html

Committed: https://src.chromium.org/viewvc/blink?view=rev&revision=178918

[haraken, 2014-07-25 02:51:01]

PTAL

[dcarney, 2014-07-25 07:25:36]

lgtm

[haraken, 2014-07-25 08:02:21]

The CQ bit was checked by haraken@chromium.org

[commit-bot: I haz the power, 2014-07-25 08:02:59]

CQ is trying da patch. Follow status at
 https://chromium-status.appspot.com/cq/haraken@chromium.org/419683003/40001

[commit-bot: I haz the power, 2014-07-25 09:29:48]

Change committed as 178918