Clicking tab close with option key close the other tabs.

chrome/browser/ui/cocoa/tabs/tab_strip_controller.mm

Index: chrome/browser/ui/cocoa/tabs/tab_strip_controller.mm
diff --git a/chrome/browser/ui/cocoa/tabs/tab_strip_controller.mm b/chrome/browser/ui/cocoa/tabs/tab_strip_controller.mm
index d63f04f61d8d3b144051f038dc6d0bd4e0b8a7b8..d4b22d4cf521bdda7b853fdd604a168ca9be90c3 100644
--- a/chrome/browser/ui/cocoa/tabs/tab_strip_controller.mm
+++ b/chrome/browser/ui/cocoa/tabs/tab_strip_controller.mm
@@ -743,6 +743,16 @@ private:
   }
 }
 
+// Called when the user closes all tabs except for the current tab.
+// Invoke the |CommandCloseOtherTabs| context menu command.
+- (void)closeOtherTabs:(id)sender {
+  int index = [self modelIndexForTabView:sender];
+  if (tabStripModel_->ContainsIndex(index)) {
+    tabStripModel_->ExecuteContextMenuCommand(
+        index, TabStripModel::CommandCloseOtherTabs);
+  }
+}
+
 // Dispatch context menu commands for the given tab controller.
 - (void)commandDispatch:(TabStripModel::ContextMenuCommand)command
           forController:(TabController*)controller {