Fix crash in ProfileMenuController::validateMenuItem.

chrome/browser/ui/cocoa/profiles/profile_menu_controller.mm

 // Copyright 2014 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/profiles/profile_menu_controller.h"
 
 #include "base/mac/scoped_nsobject.h"
+#include "base/metrics/histogram_macros.h"
 #include "base/strings/sys_string_conversions.h"
 #include "chrome/browser/browser_process.h"
 #include "chrome/browser/profiles/avatar_menu.h"
 #include "chrome/browser/profiles/avatar_menu_observer.h"
 #include "chrome/browser/profiles/profile.h"
 #include "chrome/browser/profiles/profile_avatar_icon_util.h"
 #include "chrome/browser/profiles/profile_info_cache.h"
 #include "chrome/browser/profiles/profile_info_interface.h"
 #include "chrome/browser/profiles/profile_manager.h"
 #include "chrome/browser/profiles/profile_metrics.h"
 #include "chrome/browser/profiles/profile_window.h"
 #include "chrome/browser/ui/browser.h"
 #include "chrome/browser/ui/browser_list.h"
 #include "chrome/browser/ui/browser_list_observer.h"
 #include "chrome/browser/ui/cocoa/last_active_browser_cocoa.h"
 #include "chrome/grit/generated_resources.h"
 #include "components/signin/core/common/profile_management_switches.h"
 #include "ui/base/l10n/l10n_util_mac.h"
 #include "ui/gfx/image/image.h"
 
+namespace {
+  enum ValidateMenuItemSelector {

[Alexei Svitkine (slow), 2015/04/22 16:55:25]

Don't indent within namespace. Add a comment that this is used in an UMA macro
and that entries shouldn't be renumbered or removed.

[anthonyvd, 2015/04/23 14:49:01]

Done.

+    UNKNOWN_SELECTOR,
+    NEW_PROFILE,
+    EDIT_PROFILE,
+    SWITCH_PROFILE_MENU,
+    SWITCH_PROFILE_DOCK,
+    MAX_VALIDATE_MENU_SELECTOR,
+  };
+}
+
 @interface ProfileMenuController (Private)
 - (void)initializeMenu;
 @end
 
 namespace ProfileMenuControllerInternal {
 
 class Observer : public chrome::BrowserListObserver,
                  public AvatarMenuObserver {
  public:
   Observer(ProfileMenuController* controller) : controller_(controller) {
@@ skipping 124 matching lines @@
 
 - (BOOL)validateMenuItem:(NSMenuItem*)menuItem {
   // In guest mode, chrome://settings isn't available, so disallow creating
   // or editing a profile.
   Profile* activeProfile = ProfileManager::GetLastUsedProfile();
   if (activeProfile->IsGuestSession()) {
     return [menuItem action] != @selector(newProfile:) &&
            [menuItem action] != @selector(editProfile:);
   }
 
-  const AvatarMenu::Item& itemData = avatarMenu_->GetItemAt(
-      avatarMenu_->GetActiveProfileIndex());
+  size_t index = avatarMenu_->GetActiveProfileIndex();
+  if (avatarMenu_->GetNumberOfItems() <= index) {
+    ValidateMenuItemSelector current_selector = UNKNOWN_SELECTOR;
+    if ([menuItem action] == @selector(newProfile:))
+      current_selector = NEW_PROFILE;
+    else if ([menuItem action] == @selector(editProfile:))
+      current_selector = EDIT_PROFILE;
+    else if ([menuItem action] == @selector(switchToProfileFromMenu:))
+      current_selector = SWITCH_PROFILE_MENU;
+    else if ([menuItem action] == @selector(switchToProfileFromDock:))
+      current_selector = SWITCH_PROFILE_DOCK;
+    UMA_HISTOGRAM_ENUMERATION("ValidateMenuItemInvalidIndexSelector",

[Alexei Svitkine (slow), 2015/04/22 16:55:25]

Histograms use a dotted naming notation - e.g. Foo.Bar.Baz. Please update these
names to use that, nesting them under some existing category (Profiles?).

[anthonyvd, 2015/04/23 14:49:01]

Done.

+                              current_selector,
+                              MAX_VALIDATE_MENU_SELECTOR);
+    UMA_HISTOGRAM_CUSTOM_COUNTS("ValidateMenuItemInvalidIndexProfileCount",
+                                avatarMenu_->GetNumberOfItems(),
+                                1, 20, 20);
+    UMA_HISTOGRAM_BOOLEAN("ValidateMenuItemInvalidIndexIsGuest",
+                          activeProfile->IsGuestSession());
+
+    return NO;
+  }
+
+  const AvatarMenu::Item& itemData = avatarMenu_->GetItemAt(index);
   if ([menuItem action] == @selector(switchToProfileFromDock:) ||
       [menuItem action] == @selector(switchToProfileFromMenu:)) {
     if (!itemData.legacy_supervised)
       return YES;
 
     return [menuItem tag] == static_cast<NSInteger>(itemData.menu_index);
   }
 
   if ([menuItem action] == @selector(newProfile:))
     return !itemData.legacy_supervised;
@@ skipping 79 matching lines @@
 }
 
 - (NSMenuItem*)createItemWithTitle:(NSString*)title action:(SEL)sel {
   base::scoped_nsobject<NSMenuItem> item(
       [[NSMenuItem alloc] initWithTitle:title action:sel keyEquivalent:@""]);
   [item setTarget:self];
   return [item.release() autorelease];
 }
 
 @end