This fixes bug http://code.google.com/p/chromium/issues/detail?id=3881, which...

webkit/glue/webplugin_impl.cc

 // Copyright (c) 2006-2008 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 "config.h"
 
 #include "base/compiler_specific.h"
 #include "build/build_config.h"
 
 MSVC_PUSH_WARNING_LEVEL(0);
@@ skipping 170 matching lines @@
     // This is to force an updategeometry call to the plugin process
     // where the plugin window can be hidden or shown.
     frameRectsChanged();
   }
 }
 
 void WebPluginContainer::handleEvent(WebCore::Event* event) {
   impl_->handleEvent(event);
 }
 
+void WebPluginContainer::frameRectsChanged() const {
+  WebCore::Widget::frameRectsChanged();
+  // This is a hack to tickle re-positioning of the plugin in the case where
+  // our parent view was scrolled.
+  impl_->setFrameRect(frameRect());
+}
+
+// We override this function, to make sure that geometry updates are sent
+// over to the plugin. For e.g. when a plugin is instantiated it does
+// not have a valid parent. As a result the first geometry update from
+// webkit is ignored. This function is called when the plugin eventually
+// gets a parent.
+void WebPluginContainer::setParentVisible(bool visible) {
+  WebCore::Widget::setParentVisible(visible);
+  if (visible)
+    show();
+  else
+    hide();
+}
+
 void WebPluginContainer::windowCutoutRects(const WebCore::IntRect& bounds,
                                            WTF::Vector<WebCore::IntRect>*
                                            cutouts) const {
   impl_->windowCutoutRects(bounds, cutouts);
 }
 
 void WebPluginContainer::didReceiveResponse(
     const WebCore::ResourceResponse& response) {
 
   HttpResponseInfo http_response_info;
@@ skipping 382 matching lines @@
         if (!ro->style() || ro->style()->visibility() == WebCore::VISIBLE) {
           int x, y;
           ro->absolutePosition(x, y);
           cutouts->append(WebCore::IntRect(x, y, ro->width(), ro->height()));
         }
       }
     }
   }
 }
 
-void WebPluginImpl::geometryChanged() const {
-  if (!widget_)
-    return;
-
-  // This is a hack to tickle re-positioning of the plugin in the case where
-  // our parent view was scrolled.
-  const_cast<WebPluginImpl*>(this)->widget_->setFrameRect(
-      widget_->frameRect());
-}
-
 void WebPluginImpl::setFrameRect(const WebCore::IntRect& rect) {
   // Compute a new position and clip rect for ourselves relative to the
   // containing window.  We ask our delegate to reposition us accordingly.
 
   // When the plugin is loaded we don't have a parent frame yet. We need
   // to force the plugin window to get created in the plugin process,
   // when the plugin widget position is updated. This occurs just after
   // the plugin is loaded (See http://b/issue?id=892174).
   if (!parent()) {
     force_geometry_update_ = true;
@@ skipping 668 matching lines @@
 
   MultiPartResponseClient* multi_part_response_client =
       new MultiPartResponseClient(client);
 
   MultipartResponseDelegate* multi_part_response_handler =
       new MultipartResponseDelegate(multi_part_response_client, NULL,
                                     response,
                                     multipart_boundary);
   multi_part_response_map_[client] = multi_part_response_handler;
 }