Experiment to hide close buttons of inactive tabs when using touch

chrome/browser/ui/tabs/tab_utils.h

 // 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.
 
 #ifndef CHROME_BROWSER_UI_TABS_TAB_UTILS_H_
 #define CHROME_BROWSER_UI_TABS_TAB_UTILS_H_
 
 #include <vector>
 
 #include "base/memory/scoped_ptr.h"
@@ skipping 28 matching lines @@
 //
 // Precedence rules for deciding what to show when capacity is insufficient to
 // show everything:
 //
 //   Active tab: Always show the close button, then the media indicator, then
 //               the favicon.
 //   Inactive tab: Media indicator, then the favicon, then the close button.
 //   Pinned tab: Show only the media indicator, or only the favicon
 //               (TAB_MEDIA_STATE_NONE).  Never show the close button.
 bool ShouldTabShowFavicon(int capacity,
+                          int width,
+                          bool touch_used_last,
                           bool is_pinned_tab,
                           bool is_active_tab,
                           bool has_favicon,
                           TabMediaState media_state);
 bool ShouldTabShowMediaIndicator(int capacity,
+                                 int width,
+                                 bool touch_used_last,
                                  bool is_pinned_tab,
                                  bool is_active_tab,
                                  bool has_favicon,
                                  TabMediaState media_state);
 bool ShouldTabShowCloseButton(int capacity,
+                              int width,
+                              bool touch_used_last,
                               bool is_pinned_tab,
                               bool is_active_tab);
 
 // Returns whether the given |contents| is playing audio. We might choose to
 // show an audio favicon indicator for this tab.
 bool IsPlayingAudio(content::WebContents* contents);
 
 // Returns the media state to be shown by the tab's media indicator.  When
 // multiple states apply (e.g., tab capture with audio playback), the one most
 // relevant to user privacy concerns is selected.
@@ skipping 32 matching lines @@
 bool IsTabAudioMuted(content::WebContents* contents);
 void SetTabAudioMuted(content::WebContents* contents, bool mute);
 
 // Returns true if the tabs at the |indices| in |tab_strip| are all muted.
 bool AreAllTabsMuted(const TabStripModel& tab_strip,
                      const std::vector<int>& indices);
 
 }  // namespace chrome
 
 #endif  // CHROME_BROWSER_UI_TABS_TAB_UTILS_H_