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::typingAddedToOpenCommand(
    ETypingCommand commandTypeForAddedTyping) {
  LocalFrame* frame = document().frame();
  if (!frame)
    return;

  updatePreservesTypingStyle(commandTypeForAddedTyping);
  updateCommandTypeOfOpenCommand(commandTypeForAddedTyping);

  frame->editor().appliedEditing(this);
}

void TypingCommand::typingAddedToOpenCommand(
    ETypingCommand commandTypeForAddedTyping) {
  LocalFrame* frame = document().frame();
  if (!frame)
    return;

  updatePreservesTypingStyle(commandTypeForAddedTyping);
  updateCommandTypeOfOpenCommand(commandTypeForAddedTyping);

  frame->editor().appliedEditing(this);
}
