While screencasting a tab, do not disable rendering updates while hidden.

chrome/browser/ui/gtk/tabs/dragged_tab_controller_gtk.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/gtk/tabs/dragged_tab_controller_gtk.h"
 
 #include <algorithm>
 
 #include "base/bind.h"
 #include "base/bind_helpers.h"
@@ skipping 417 matching lines @@
     // There is no tab in |attached_tabstrip| that corresponds to the dragged
     // WebContents. We must now create one.
 
     // Remove ourselves as the delegate now that the dragged WebContents
     // is being inserted back into a Browser.
     for (size_t i = 0; i < drag_data_->size(); ++i) {
       drag_data_->get(i)->contents_->SetDelegate(NULL);
       drag_data_->get(i)->original_delegate_ = NULL;
     }
 
-    // Return the WebContents to normalcy.
-    drag_data_->GetSourceWebContents()->SetCapturingContents(false);
-
     // We need to ask the tabstrip we're attached to ensure that the ideal
     // bounds for all its tabs are correctly generated, because the calculation
     // in GetInsertionIndexForDraggedBounds needs them to be to figure out the
     // appropriate insertion index.
     attached_tabstrip_->GenerateIdealBounds();
 
     // Inserting counts as a move. We don't want the tabs to jitter when the
     // user moves the tab immediately after attaching it.
     last_move_screen_x_ = screen_point.x();
 
@@ skipping 430 matching lines @@
 
 bool DraggedTabControllerGtk::AreTabsConsecutive() {
   for (size_t i = 1; i < drag_data_->size(); ++i) {
     if (drag_data_->get(i - 1)->source_model_index_ + 1 !=
         drag_data_->get(i)->source_model_index_) {
       return false;
     }
   }
   return true;
 }