Disable zoom-in and zoom-out buttons in toolbar menu for a crashed page.

chrome/browser/ui/views/toolbar/app_menu.cc

 // Copyright 2013 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/toolbar/app_menu.h"
 
 #include <stdint.h>
 
 #include <algorithm>
 #include <cmath>
@@ skipping 648 matching lines @@
   }
 
   void UpdateZoomControls() {
     WebContents* selected_tab = GetActiveWebContents();
     int zoom = 100;
     if (selected_tab) {
       auto zoom_controller =
           ui_zoom::ZoomController::FromWebContents(selected_tab);
       if (zoom_controller)
         zoom = zoom_controller->GetZoomPercent();
-      increment_button_->SetEnabled(zoom <
-                                    selected_tab->GetMaximumZoomPercent());
-      decrement_button_->SetEnabled(zoom >
-                                    selected_tab->GetMinimumZoomPercent());
+      increment_button_->SetEnabled(
+          !selected_tab->IsCrashed() &&
+          zoom < selected_tab->GetMaximumZoomPercent());
+      decrement_button_->SetEnabled(
+          !selected_tab->IsCrashed() &&
+          zoom > selected_tab->GetMinimumZoomPercent());

[Peter Kasting, 2016/04/12 23:39:56]

It feels wrong that we duplicate this logic both here and in
browser_commands.cc.  Can we put an appropriate function/pair of functions
somewhere both places can call instead?

[Tom (Use chromium acct), 2016/04/14 19:19:36]

Done.

     }
     zoom_label_->SetText(
         l10n_util::GetStringFUTF16Int(IDS_ZOOM_PERCENT, zoom));
 
     zoom_label_max_width_valid_ = false;
   }
 
   // Returns the max width the zoom string can be.
   int ZoomLabelMaxWidth() const {
     if (!zoom_label_max_width_valid_) {
@@ skipping 606 matching lines @@
                                 0,
                                 BookmarkMenuDelegate::SHOW_PERMANENT_FOLDERS,
                                 BOOKMARK_LAUNCH_LOCATION_APP_MENU);
 }
 
 int AppMenu::ModelIndexFromCommandId(int command_id) const {
   CommandIDToEntry::const_iterator ix = command_id_to_entry_.find(command_id);
   DCHECK(ix != command_id_to_entry_.end());
   return ix->second.second;
 }