Make TypingCommand::insertText() to take SelectionInDOMTree instead of VisibleSelection

This patch makes |TypingCommand::insertText()| to take |SelectionInDOMTree|
instead of |VisibleSelection| to reduce usage of |VisibleSelection| for
improving code health.

BUG=657237
TEST=n/a

Review-Url: https://codereview.chromium.org/2733183002
Cr-Commit-Position: refs/heads/master@{#455368}
void TypingCommand::deleteSelectionIfRange(const VisibleSelection& selection,
                                           EditingState* editingState,
                                           bool smartDelete,
                                           bool mergeBlocksAfterDelete,
                                           bool expandForSpecialElements,
                                           bool sanitizeMarkup) {
  if (!selection.isRange())
    return;
  applyCommandToComposite(DeleteSelectionCommand::create(
                              selection, smartDelete, mergeBlocksAfterDelete,
                              expandForSpecialElements, sanitizeMarkup),
                          editingState);
}

void TypingCommand::deleteSelectionIfRange(const VisibleSelection& selection,
                                           EditingState* editingState,
                                           bool smartDelete,
                                           bool mergeBlocksAfterDelete,
                                           bool expandForSpecialElements,
                                           bool sanitizeMarkup) {
  if (!selection.isRange())
    return;
  applyCommandToComposite(DeleteSelectionCommand::create(
                              selection, smartDelete, mergeBlocksAfterDelete,
                              expandForSpecialElements, sanitizeMarkup),
                          editingState);
}
