Propagate view background color when changing visible web contents.

content/browser/web_contents/web_contents_impl.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 "content/browser/web_contents/web_contents_impl.h"
 
 #include <stddef.h>
 
 #include <cmath>
 #include <utility>
@@ skipping 3968 matching lines @@
     observer.RenderViewHostChanged(old_host, new_host);
 
   // Ensure that the associated embedder gets cleared after a RenderViewHost
   // gets swapped, so we don't reuse the same embedder next time a
   // RenderViewHost is attached to this WebContents.
   RemoveBrowserPluginEmbedder();
 }
 
 void WebContentsImpl::NotifyFrameSwapped(RenderFrameHost* old_host,
                                          RenderFrameHost* new_host) {
+  // Copies the background color from an old WebContents to a new one that
+  // replaces it on the screen. This allows the new WebContents to use the
+  // old one's background color as the starting background color, before having
+  // loaded any contents. As a result, we avoid flashing white when navigating
+  // from a site whith a dark background to another site with a dark background.
+  if (old_host && new_host) {
+    RenderWidgetHostView* old_view = old_host->GetView();
+    RenderWidgetHostView* new_view = new_host->GetView();
+    if (old_view && new_view)
+      new_view->SetBackgroundColor(old_view->background_color());
+  }
+
   for (auto& observer : observers_)
     observer.RenderFrameHostChanged(old_host, new_host);
 }
 
 // TODO(avi): Remove this entire function because this notification is already
 // covered by two observer functions. http://crbug.com/170921
 void WebContentsImpl::NotifyDisconnected() {
   if (!notify_disconnection_)
     return;
 
@@ skipping 1199 matching lines @@
   dialog_manager_ = dialog_manager;
 }
 
 void WebContentsImpl::RemoveBindingSet(const std::string& interface_name) {
   auto it = binding_sets_.find(interface_name);
   if (it != binding_sets_.end())
     binding_sets_.erase(it);
 }
 
 }  // namespace content