Enforce that only one constrained window is displayed at once per tab.

chrome/browser/tab_contents/tab_contents.cc

 // Copyright (c) 2009 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/tab_contents/tab_contents.h"
 
 #include "app/gfx/text_elider.h"
 #include "app/l10n_util.h"
 #include "app/resource_bundle.h"
 #include "base/file_version_info.h"
@@ skipping 806 matching lines @@
     return;
 
   delegate_->ShowPageInfo(profile(), url, ssl, show_history);
 }
 
 ConstrainedWindow* TabContents::CreateConstrainedDialog(
       ConstrainedWindowDelegate* delegate) {
   ConstrainedWindow* window =
       ConstrainedWindow::CreateConstrainedDialog(this, delegate);
   child_windows_.push_back(window);
+
+  if (child_windows_.size() == 1)
+    window->ShowConstrainedWindow();
+
   return window;
 }
 
 void TabContents::AddNewContents(TabContents* new_contents,
                                  WindowOpenDisposition disposition,
                                  const gfx::Rect& initial_pos,
                                  bool user_gesture,
                                  const GURL& creator_url) {
   if (!delegate_)
     return;
@@ skipping 210 matching lines @@
   // Download in a constrained popup is shown in the tab that opened it.
   TabContents* tab_contents = delegate()->GetConstrainingContents(this);
 
   if (tab_contents && tab_contents->delegate())
     tab_contents->delegate()->OnStartDownload(download);
 }
 
 void TabContents::WillClose(ConstrainedWindow* window) {
   ConstrainedWindowList::iterator it =
       find(child_windows_.begin(), child_windows_.end(), window);
+
+  bool removed_topmost_window = it == child_windows_.begin();
   if (it != child_windows_.end())
     child_windows_.erase(it);
+
+  if (removed_topmost_window && child_windows_.size() > 0)
+    child_windows_[0]->ShowConstrainedWindow();
 }
 
 void TabContents::WillCloseBlockedPopupContainer(
     BlockedPopupContainer* container) {
   DCHECK(blocked_popups_ == container);
   blocked_popups_ = NULL;
 }
 
 void TabContents::DidMoveOrResize(ConstrainedWindow* window) {
 #if defined(OS_WIN)
@@ skipping 1642 matching lines @@
   render_view_host()->JavaScriptMessageBoxClosed(reply_msg, success, prompt);
 }
 
 void TabContents::SetSuppressMessageBoxes(bool suppress_message_boxes) {
   set_suppress_javascript_messages(suppress_message_boxes);
 }
 
 void TabContents::set_encoding(const std::string& encoding) {
   encoding_ = CharacterEncoding::GetCanonicalEncodingNameByAliasName(encoding);
 }