[temporary M30 fix] Disable dragging tabs with web contents modal dialogs displayed

chrome/browser/ui/views/tabs/tab_strip.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 "chrome/browser/ui/views/tabs/tab_strip.h"
 
 #if defined(OS_WIN)
 #include <windowsx.h>
 #endif
 
@@ skipping 1109 matching lines @@
   // is maximized or fullscreen, we know there are no other tabbed browsers the
   // user can drag to.
   const chrome::HostDesktopType host_desktop_type =
       chrome::GetHostDesktopTypeForNativeView(widget->GetNativeView());
   if (host_desktop_type == chrome::HOST_DESKTOP_TYPE_ASH &&
       (widget->IsMaximized() || widget->IsFullscreen()) &&
       static_cast<int>(tabs.size()) == tab_count() &&
       gfx::Screen::GetScreenFor(widget->GetNativeView())->GetNumDisplays() == 1)
     detach_behavior = TabDragController::NOT_DETACHABLE;
 
+#if defined(OS_CHROMEOS)
+  // TODO(wittman): This is a temporary workaround to avoid crbug.com/275274 and
+  // crbug.com/274856 in M30 and should be reverted after merge, as we have a
+  // solution to these bugs in trunk.
+  //
+  // Don't allow detaching if the tab has a WebContentsModalDialogView opened.
+  if (controller()->IsTabShowingWebViewModalDialog(GetModelIndexOfTab(tab)))
+    detach_behavior = TabDragController::NOT_DETACHABLE;
+#endif
+
 #if defined(OS_WIN)
   // It doesn't make sense to drag tabs out on Win8's single window Metro mode.
   if (win8::IsSingleWindowMetroMode())
     detach_behavior = TabDragController::NOT_DETACHABLE;
 #endif
   // Gestures don't automatically do a capture. We don't allow multiple drags at
   // the same time, so we explicitly capture.
   if (event.type() == ui::ET_GESTURE_BEGIN)
     widget->SetCapture(this);
   drag_controller_.reset(new TabDragController);
@@ skipping 1572 matching lines @@
   if (!adjust_layout_)
     return false;
 
 #if !defined(OS_CHROMEOS)
   if (ui::GetDisplayLayout() != ui::LAYOUT_TOUCH)
     return false;
 #endif
 
   return true;
 }