Show status bubble for links that have keyboard focus....

chrome/renderer/render_view.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/renderer/render_view.h"
 
 #include <algorithm>
 #include <string>
 #include <vector>
 
@@ skipping 1594 matching lines @@
 }
 
 void RenderView::showContextMenu(
     WebFrame* frame, const WebContextMenuData& data) {
   Send(new ViewHostMsg_ContextMenu(routing_id_, ContextMenuParams(data)));
 }
 
 void RenderView::setStatusText(const WebString& text) {
 }
 
-void RenderView::setMouseOverURL(const WebURL& url) {
-  GURL latest_url(url);
+void RenderView::UpdateTargetURL(const GURL& url, const GURL& fallback_url) {
+  GURL latest_url = url.spec().empty() ? fallback_url : url;
   if (latest_url == target_url_)
     return;
+
   // Tell the browser to display a destination link.
   if (target_url_status_ == TARGET_INFLIGHT ||
       target_url_status_ == TARGET_PENDING) {
     // If we have a request in-flight, save the URL to be sent when we
     // receive an ACK to the in-flight request. We can happily overwrite
     // any existing pending sends.
     pending_target_url_ = latest_url;
     target_url_status_ = TARGET_PENDING;
   } else {
     Send(new ViewHostMsg_UpdateTargetURL(routing_id_, page_id_, latest_url));
     target_url_ = latest_url;
     target_url_status_ = TARGET_INFLIGHT;
   }
 }
 
+void RenderView::setMouseOverURL(const WebURL& url) {
+  mouse_over_url_ = GURL(url);
+  UpdateTargetURL(mouse_over_url_, focus_url_);
+}
+
+void RenderView::setKeyboardFocusURL(const WebURL& url) {
+  focus_url_ = GURL(url);
+  UpdateTargetURL(focus_url_, mouse_over_url_);
+}
+
 void RenderView::setToolTipText(const WebString& text, WebTextDirection hint) {
   Send(new ViewHostMsg_SetTooltipText(routing_id_, UTF16ToWideHack(text),
                                       hint));
 }
 
 void RenderView::startDragging(const WebPoint& from, const WebDragData& data,
                                WebDragOperationsMask allowed_ops) {
   Send(new ViewHostMsg_StartDragging(routing_id_,
                                      WebDropData(data),
                                      allowed_ops));
@@ skipping 2038 matching lines @@
       new PluginMsg_SignalModalDialogEvent(host_window_));
 
   message->EnableMessagePumping();  // Runs a nested message loop.
   bool rv = Send(message);
 
   PluginChannelHost::Broadcast(
       new PluginMsg_ResetModalDialogEvent(host_window_));
 
   return rv;
 }