Omnibox UI Experiments: Make suggestions dropdown match omnibox width.

chrome/browser/ui/views/location_bar/location_bar_view.cc

Index: chrome/browser/ui/views/location_bar/location_bar_view.cc
diff --git a/chrome/browser/ui/views/location_bar/location_bar_view.cc b/chrome/browser/ui/views/location_bar/location_bar_view.cc
index 3603e712f0d65f4ad2d707fc789b944f2e1fcee7..5b654ff973887ad8235534cd290af03dce7041c3 100644
--- a/chrome/browser/ui/views/location_bar/location_bar_view.cc
+++ b/chrome/browser/ui/views/location_bar/location_bar_view.cc
@@ -7,6 +7,7 @@
 #include <algorithm>
 #include <map>
 
+#include "base/feature_list.h"
 #include "base/i18n/rtl.h"
 #include "base/memory/ptr_util.h"
 #include "base/strings/utf_string_conversions.h"
@@ -49,6 +50,7 @@
 #include "chrome/grit/chromium_strings.h"
 #include "components/bookmarks/common/bookmark_pref_names.h"
 #include "components/favicon/content/content_favicon_driver.h"
+#include "components/omnibox/browser/omnibox_field_trial.h"
 #include "components/omnibox/browser/omnibox_popup_model.h"
 #include "components/omnibox/browser/omnibox_popup_view.h"
 #include "components/prefs/pref_service.h"
@@ -369,12 +371,16 @@ void LocationBarView::GetOmniboxPopupPositioningInfo(
     int* left_margin,
     int* right_margin,
     int top_edge_overlap) {
-  *top_left_screen_coord = gfx::Point(0, parent()->height() - top_edge_overlap);
+  bool narrow_popup =
+      base::FeatureList::IsEnabled(omnibox::kUIExperimentNarrowDropdown);
+
+  *top_left_screen_coord =
+      gfx::Point(narrow_popup ? x() : 0, parent()->height() - top_edge_overlap);
   views::View::ConvertPointToScreen(parent(), top_left_screen_coord);
 
-  *popup_width = parent()->width();
-  *left_margin = x();
-  *right_margin = *popup_width - bounds().right();
+  *popup_width = narrow_popup ? width() : parent()->width();
+  *left_margin = narrow_popup ? 0 : x();
+  *right_margin = narrow_popup ? 0 : *popup_width - bounds().right();

[Peter Kasting, 2017/06/09 02:17:53]

Nit: Reading this, it felt a bit cryptic and error-prone.  This felt a bit
clearer, and with fewer conditionals:

  // The popup contents are always sized matching the location bar size.
  const int popup_contents_left = x();
  const int popup_contents_right = bounds().right();

  // The popup itself may either be the same width as the contents, or as wide
  // as the toolbar.
  const bool narrow_popup = ...;
  const int popup_left = narrow_popup ? popup_contents_left : 0;
  const int popup_right =
      narrow_popup ? popup_contents_right : parent()->width();

  *top_left_screen_coord = gfx::Point(popup_left, ...);
  ...

  *popup_width = popup_right - popup_left;
  *left_margin = popup_contents_left - popup_left;
  *right_margin = popup_right - popup_contents_right;

[tommycli, 2017/06/09 16:26:51]

Done.

 }
 
 ////////////////////////////////////////////////////////////////////////////////