Omnibox UI Experiments: Add Vertical Layout experiment (title-on-top).

components/omnibox/browser/omnibox_popup_model.cc

 // Copyright (c) 2012 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "components/omnibox/browser/omnibox_popup_model.h"
 
 #include <algorithm>
 
+#include "base/feature_list.h"
 #include "base/strings/string_util.h"
 #include "base/strings/utf_string_conversions.h"
 #include "components/bookmarks/browser/bookmark_model.h"
 #include "components/omnibox/browser/autocomplete_match.h"
 #include "components/omnibox/browser/omnibox_client.h"
+#include "components/omnibox/browser/omnibox_field_trial.h"
 #include "components/omnibox/browser/omnibox_popup_model_observer.h"
 #include "components/omnibox/browser/omnibox_popup_view.h"
 #include "components/search_engines/template_url.h"
 #include "components/search_engines/template_url_service.h"
 #include "third_party/icu/source/common/unicode/ubidi.h"
 #include "ui/gfx/geometry/rect.h"
 #include "ui/gfx/image/image.h"
 
 using bookmarks::BookmarkModel;
 
@@ skipping 24 matching lines @@
                                               bool description_on_separate_line,
                                               bool allow_shrinking_contents,
                                               int* contents_max_width,
                                               int* description_max_width) {
   available_width = std::max(available_width, 0);
   *contents_max_width = std::min(contents_width, available_width);
   *description_max_width = std::min(description_width, available_width);
 
   // If the description is empty, or the contents and description are on
   // separate lines, each can get the full available width.
-  if (!description_width || description_on_separate_line)
+  if (!description_width || description_on_separate_line ||

[Peter Kasting, 2017/05/25 20:24:39]

I feel like the caller should have passed true for
|description_on_separate_line|, rather than checking it internally here.

This would also make for better testability, since you can specify the behavior
you want directly in the test.

[tommycli, 2017/05/25 21:59:10]

Done.

+      base::FeatureList::IsEnabled(omnibox::kUIExperimentVerticalLayout)) {

[Peter Kasting, 2017/05/25 20:24:39]

Nit: Omnibox code doesn't usually use braces for cases like this

[tommycli, 2017/05/25 21:59:10]

Done.

     return;
+  }
 
   // If we want to display the description, we need to reserve enough space for
   // the separator.
   available_width -= separator_width;
   if (available_width < 0) {
     *description_max_width = 0;
     return;
   }
 
   if (contents_width + description_width > available_width) {
@@ skipping 224 matching lines @@
 }
 
 void OmniboxPopupModel::RemoveObserver(OmniboxPopupModelObserver* observer) {
   observers_.RemoveObserver(observer);
 }
 
 void OmniboxPopupModel::SetAnswerBitmap(const SkBitmap& bitmap) {
   answer_bitmap_ = bitmap;
   view_->UpdatePopupAppearance();
 }