[V8] Remove the world->isMainWorld() check from minorGCPrologue()

[Kentaro Hara]

A couple of weeks ago, I introduced the following check to minorGCPrologue() in r142419.

  void minorGCPrologue() {
    // A minor GC can handle the main world only.
    DOMWrapperWorld* world = worldForEnteredContextWithoutContextCheck();
    if (world && world->isMainWorld()) {
      MinorGCWrapperVisitor visitor(isolate);
      v8::V8::VisitHandlesForPartialDependence(isolate, &visitor);
      visitor.notifyFinished();
    }
  }

- The check makes no sense. A GC should not care about what world we are in. There is no concept of worlds in GC.

- worldForEnteredContextWithoutContextCheck() returns 0 for the main world. So if a GC runs in the main world, the minor DOM GC is skipped.

- worldForEnteredContextWithoutContextCheck() caused a Chromium crash (https://code.google.com/p/chromium/issues/detail?id=177587)

We should remove the check.

[Kentaro Hara]

Created attachment 190810 [details]
Patch

[Kentaro Hara]

Created attachment 190811 [details]
Patch

[WebKit Review Bot]

Comment on attachment 190811 [details]
Patch

Clearing flags on attachment: 190811

Committed r144381: <http://trac.webkit.org/changeset/144381>

[WebKit Review Bot]

All reviewed patches have been landed.  Closing bug.