Tab audio mute control (views UI), behind a switch (off by default).

chrome/browser/ui/views/tabs/tab_controller.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_VIEWS_TABS_TAB_CONTROLLER_H_
 #define CHROME_BROWSER_UI_VIEWS_TABS_TAB_CONTROLLER_H_
 
 #include "chrome/browser/ui/views/tabs/tab_strip_types.h"
 
 class Tab;
@@ skipping 26 matching lines @@
 
   // Toggles whether |tab| is selected.
   virtual void ToggleSelected(Tab* tab) = 0;
 
   // Adds the selection from the anchor to |tab|.
   virtual void AddSelectionFromAnchorTo(Tab* tab) = 0;
 
   // Closes the tab.
   virtual void CloseTab(Tab* tab, CloseTabSource source) = 0;
 
+  // Toggles whether tab-wide audio muting is active.
+  virtual void ToggleTabAudioMute(Tab* tab) = 0;
+
   // Shows a context menu for the tab at the specified point in screen coords.
   virtual void ShowContextMenuForTab(Tab* tab,
                                      const gfx::Point& p,
                                      ui::MenuSourceType source_type) = 0;
 
   // Returns true if |tab| is the active tab. The active tab is the one whose
   // content is shown in the browser.
   virtual bool IsActiveTab(const Tab* tab) const = 0;
 
   // Returns true if the specified Tab is selected.
@@ skipping 34 matching lines @@
 
   // Adds private information to the tab's accessibility state.
   virtual void UpdateTabAccessibilityState(const Tab* tab,
                                         ui::AXViewState* state) = 0;
 
  protected:
   virtual ~TabController() {}
 };
 
 #endif  // CHROME_BROWSER_UI_VIEWS_TABS_TAB_CONTROLLER_H_