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 f23d8467e16dc0ae5204caed528a6548a86403d3..a962a9e1518d1226bc0f1cfada820fa748c3ae11 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"
@@ -51,6 +52,7 @@
 #include "chrome/grit/generated_resources.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"
@@ -370,12 +372,25 @@ 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);
+  // 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.
+  bool narrow_popup =
+      base::FeatureList::IsEnabled(omnibox::kUIExperimentNarrowDropdown);
+  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, 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 = popup_right - popup_left;
+  *left_margin = popup_contents_left - popup_left;
+  *right_margin = popup_right - popup_contents_right;
 }
 
 ////////////////////////////////////////////////////////////////////////////////