Mac: Make calling WebContents::WasShown/WasHidden the responsibility of the content layer

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

 // 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.
 
 #import "chrome/browser/ui/cocoa/tabs/tab_strip_controller.h"
 
 #import <QuartzCore/QuartzCore.h>
 
 #include <cmath>
 #include <limits>
@@ skipping 661 matching lines @@
   // may not be any children in the case of a tab that's been closed, in
   // which case there's no swapping going on.
   NSArray* subviews = [switchView_ subviews];
   if ([subviews count]) {
     NSView* oldView = [subviews objectAtIndex:0];
     // Set newView frame to the oldVew frame to prevent NSSplitView hosting
     // sidebar and tab content from resizing sidebar's content view.
     // ensureContentsVisible (see below) sets content size and autoresizing
     // properties.
     [newView setFrame:[oldView frame]];
-    [switchView_ replaceSubview:oldView with:newView];
+    // Remove the old view first, to ensure ConstrainedWindowSheets keyed to the
+    // old WebContents are removed before adding new ones.

[Avi (use Gerrit), 2016/02/29 17:27:23]

As a side note, this sounds like a limitation of the constrained window code
that should be fixed. :)

+    [oldView removeFromSuperview];
+    [switchView_ addSubview:newView];
   } else {
     [newView setFrame:[switchView_ bounds]];
     [switchView_ addSubview:newView];
   }
 
   // New content is in place, delegate should adjust itself accordingly.
   [delegate_ onActivateTabWithContents:[controller webContents]];
 
   // It also restores content autoresizing properties.
   [controller ensureContentsVisible];
@@ skipping 676 matching lines @@
                          reason:(int)reason {
   // Take closing tabs into account.
   if (oldContents) {
     int oldModelIndex =
         browser_->tab_strip_model()->GetIndexOfWebContents(oldContents);
     if (oldModelIndex != -1) {  // When closing a tab, the old tab may be gone.
       NSInteger oldIndex = [self indexFromModelIndex:oldModelIndex];
       TabContentsController* oldController =
           [tabContentsArray_ objectAtIndex:oldIndex];
       [oldController willBecomeUnselectedTab];
-      oldContents->WasHidden();
     }
   }
 
   NSUInteger activeIndex = [self indexFromModelIndex:modelIndex];
 
   [tabArray_ enumerateObjectsUsingBlock:^(TabController* current,
                                           NSUInteger index,
                                           BOOL* stop) {
       [current setActive:index == activeIndex];
   }];
 
   // Tell the new tab contents it is about to become the selected tab. Here it
   // can do things like make sure the toolbar is up to date.
   TabContentsController* newController =
       [tabContentsArray_ objectAtIndex:activeIndex];
   [newController willBecomeSelectedTab];
 
   // Relayout for new tabs and to let the selected tab grow to be larger in
   // size than surrounding tabs if the user has many. This also raises the
   // selected tab to the top.
   [self layoutTabs];
 
   // Swap in the contents for the new tab.
   [self swapInTabAtIndex:modelIndex];
 
-  if (newContents) {
-    newContents->WasShown();
+  if (newContents)
     newContents->RestoreFocus();
-  }
 }
 
 - (void)tabSelectionChanged {
   // First get the vector of indices, which is allays sorted in ascending order.
   ui::ListSelectionModel::SelectedIndices selection(
       tabStripModel_->selection_model().selected_indices());
   // Iterate through all of the tabs, selecting each as necessary.
   ui::ListSelectionModel::SelectedIndices::iterator iter = selection.begin();
   int i = 0;
   for (TabController* current in tabArray_.get()) {
@@ skipping 988 matching lines @@
                     forButtonState:image_button_cell::kHoverStateBackground];
   } else {
     [[newTabButton_ cell] setImage:nil
                     forButtonState:image_button_cell::kDefaultStateBackground];
     [[newTabButton_ cell] setImage:nil
                     forButtonState:image_button_cell::kHoverStateBackground];
   }
 }
 
 @end