Experiment to hide close buttons of inactive tabs when using touch

chrome/browser/ui/views/tabs/tab_unittest.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 "chrome/browser/ui/views/tabs/tab.h"
 
 #include "base/i18n/rtl.h"
 #include "base/strings/utf_string_conversions.h"
 #include "chrome/browser/ui/tabs/tab_utils.h"
 #include "chrome/browser/ui/views/tabs/media_indicator_button.h"
@@ skipping 13 matching lines @@
   }
   ~FakeTabController() override {}
 
   void set_immersive_style(bool value) { immersive_style_ = value; }
   void set_active_tab(bool value) { active_tab_ = value; }
 
   const ui::ListSelectionModel& GetSelectionModel() override {
     return selection_model_;
   }
   bool SupportsMultipleSelection() override { return false; }
+  bool ShouldHideCloseButtonForInactiveTab(const Tab* tab) override {
+    return false;
+  }
   void SelectTab(Tab* tab) override {}
   void ExtendSelectionTo(Tab* tab) override {}
   void ToggleSelected(Tab* tab) override {}
   void AddSelectionFromAnchorTo(Tab* tab) override {}
   void CloseTab(Tab* tab, CloseTabSource source) override {}
   void ToggleTabAudioMute(Tab* tab) override {}
   void ShowContextMenuForTab(Tab* tab,
                              const gfx::Point& p,
                              ui::MenuSourceType source_type) override {}
   bool IsActiveTab(const Tab* tab) const override { return active_tab_; }
@@ skipping 340 matching lines @@
   EXPECT_EQ(50, tab.close_button_->bounds().height());
 }
 
 // Test in both a LTR and a RTL locale.  Note: The fact that the UI code is
 // configured for an RTL locale does *not* change how the coordinates are
 // examined in the tests above because views::View and friends are supposed to
 // auto-mirror the widgets when painting.  Thus, what we're testing here is that
 // there's no code in Tab that will erroneously subvert this automatic
 // coordinate translation.  http://crbug.com/384179
 INSTANTIATE_TEST_CASE_P(, TabTest, ::testing::Values(false, true));