linux: cleanup browser-side GtkSockets when plugins are destroyed

webkit/glue/plugins/webplugin_delegate_impl_gtk.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 "webkit/glue/plugins/webplugin_delegate_impl.h"
 
 #include <string>
 #include <vector>
 
 #include <gtk/gtk.h>
@@ skipping 248 matching lines @@
   NPError err = instance_->NPP_GetValue(NPPVpluginNeedsXEmbed, &xembed);
   DCHECK(err == NPERR_NO_ERROR);
   if (!xembed) {
     NOTIMPLEMENTED() << "Windowed plugin but without xembed.";
     return false;
   }
 
   window_.window = reinterpret_cast<void*>(parent_);
   // The remainder of the code expects windowed_handle_ to exist for
   // windowed mode, despite not actually ever reaching through
-  // windowed_handle_.  So let's set it to the one window handle we
-  // actually have available.
+  // windowed_handle_.  It is still used as a token to represent "this
+  // plugin" in messages to the browser.
   windowed_handle_ = parent_;
 
   if (!window_.ws_info)
     window_.ws_info = new NPSetWindowCallbackStruct;
   NPSetWindowCallbackStruct* extra =
       static_cast<NPSetWindowCallbackStruct*>(window_.ws_info);
   extra->display = GDK_DISPLAY();
   extra->visual = DefaultVisual(GDK_DISPLAY(), 0);
   extra->depth = DefaultDepth(GDK_DISPLAY(), 0);
   extra->colormap = DefaultColormap(GDK_DISPLAY(), 0);
 
   return true;
 }
 
 void WebPluginDelegateImpl::WindowedDestroyWindow() {
-  // We have no window to destroy; see comment in WindowedCreatePlugin
-  // where windowed_handle_ is set.
-  windowed_handle_ = 0;
+  if (windowed_handle_) {
+    plugin_->WillDestroyWindow(windowed_handle_);
+
+    windowed_handle_ = 0;
+  }
 }
 
 bool WebPluginDelegateImpl::WindowedReposition(
     const gfx::Rect& window_rect,
     const gfx::Rect& clip_rect) {
   if (window_rect == window_rect_ && clip_rect == clip_rect_)
     return false;
 
   window_rect_ = window_rect;
   clip_rect_ = clip_rect;
@@ skipping 541 matching lines @@
   return stream;
 }
 
 void WebPluginDelegateImpl::URLRequestRouted(const std::string&url,
                                              bool notify_needed,
                                              intptr_t notify_data) {
   if (notify_needed) {
     instance()->SetURLLoadData(GURL(url.c_str()), notify_data);
   }
 }