ash: Prevent negative sizes.

ash/system/user/tray_user.cc

 // 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.
 
 #include "ash/system/user/tray_user.h"
 
 #include <algorithm>
 #include <climits>
 #include <vector>
 
@@ skipping 414 matching lines @@
   gfx::Rect contents_area(GetContentsBounds());
   if (user_card_ && logout_button_) {
     // Give the logout button the space it requests.
     gfx::Rect logout_area = contents_area;
     logout_area.ClampToCenteredSize(logout_button_->GetPreferredSize());
     logout_area.set_x(contents_area.right() - logout_area.width());
     logout_button_->SetBoundsRect(logout_area);
 
     // Give the remaining space to the user card.
     gfx::Rect user_card_area = contents_area;
-    user_card_area.set_width(contents_area.width() -
-        (logout_area.width() + kTrayPopupPaddingBetweenItems));
+    int remaining_width = contents_area.width() -
+        (logout_area.width() + kTrayPopupPaddingBetweenItems);
+    user_card_area.set_width(std::max(0, remaining_width));
     user_card_->SetBoundsRect(user_card_area);
   } else if (user_card_) {
     user_card_->SetBoundsRect(contents_area);
   } else if (logout_button_) {
     logout_button_->SetBoundsRect(contents_area);
   }
 }
 
 void UserView::ButtonPressed(views::Button* sender, const ui::Event& event) {
   DCHECK_EQ(logout_button_, sender);
@@ skipping 192 matching lines @@
   // Check for null to avoid crbug.com/150944.
   if (avatar_) {
     avatar_->SetImage(
         ash::Shell::GetInstance()->system_tray_delegate()->GetUserImage(),
         gfx::Size(kUserIconSize, kUserIconSize));
   }
 }
 
 }  // namespace internal
 }  // namespace ash