Strip JavaScript schemas on Linux text drop

When dropping text onto the Omnibox, any leading JavaScript schemes
should be stripped to avoid a "self-XSS" attack. This stripping already
occurs in all cases except when plaintext is dropped on Linux. This CL
corrects that oversight.

Bug: 768910
Change-Id: I43af24ace4a13cf61d15a32eb9382dcdd498a062
Reviewed-on: https://chromium-review.googlesource.com/685638
Reviewed-by: Justin Donnelly <jdonnelly@chromium.org>
Commit-Queue: Eric Lawrence <elawrence@chromium.org>
Cr-Commit-Position: refs/heads/master@{#504695}
bool OmniboxViewViews::HandleEarlyTabActions(const ui::KeyEvent& event) {
  if (!views::FocusManager::IsTabTraversalKeyEvent(event))
    return false;

  if (model()->is_keyword_hint() && !event.IsShiftDown())
    return model()->AcceptKeyword(KeywordModeEntryMethod::TAB);

  if (!model()->popup_model()->IsOpen())
    return false;

  if (event.IsShiftDown() &&
      (model()->popup_model()->selected_line_state() ==
          OmniboxPopupModel::KEYWORD))
    model()->ClearKeyword();
  else
    model()->OnUpOrDownKeyPressed(event.IsShiftDown() ? -1 : 1);

  return true;
}

bool OmniboxViewViews::HandleEarlyTabActions(const ui::KeyEvent& event) {
  if (!views::FocusManager::IsTabTraversalKeyEvent(event))
    return false;

  if (model()->is_keyword_hint() && !event.IsShiftDown())
    return model()->AcceptKeyword(KeywordModeEntryMethod::TAB);

  if (!model()->popup_model()->IsOpen())
    return false;

  if (event.IsShiftDown() &&
      (model()->popup_model()->selected_line_state() ==
          OmniboxPopupModel::KEYWORD))
    model()->ClearKeyword();
  else
    model()->OnUpOrDownKeyPressed(event.IsShiftDown() ? -1 : 1);

  return true;
}
