Call didAccessInitialDocument when javascript: URLs are used.

BUG=265221
TEST=See bug for repro.

Review URL: https://chromiumcodereview.appspot.com/22572004

git-svn-id: svn://svn.chromium.org/blink/trunk@155790 bbb929c8-8fbe-4397-9dbb-9b2b20218538
static int computeOffset(WebCore::RenderObject* renderer, int x, int y)
{
    return WebCore::VisiblePosition(renderer->positionForPoint(WebCore::LayoutPoint(x, y))).deepEquivalent().computeOffsetInContainerNode();
}

static int computeOffset(WebCore::RenderObject* renderer, int x, int y)
{
    return WebCore::VisiblePosition(renderer->positionForPoint(WebCore::LayoutPoint(x, y))).deepEquivalent().computeOffsetInContainerNode();
}
