GPUPluginObject has methods to query its current window size....

o3d/gpu_plugin/gpu_plugin_object.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 <stdlib.h>
 
 #include "base/logging.h"
 #include "o3d/gpu_plugin/np_utils/np_utils.h"
 #include "o3d/gpu_plugin/gpu_plugin_object.h"
 #include "o3d/gpu_plugin/gpu_processor.h"
@@ skipping 26 matching lines @@
 }
 
 NPError GPUPluginObject::SetWindow(NPWindow* new_window) {
   if (status_ == kWaitingForNew || status_ == kDestroyed)
     return NPERR_GENERIC_ERROR;
 
   // PlatformSpecificSetWindow advances the status depending on what happens.
   NPError error = PlatformSpecificSetWindow(new_window);
   if (error == NPERR_NO_ERROR) {
     window_ = *new_window;
+
+    if (event_sync_.Get()) {
+      NPInvokeVoid(npp_,
+                   event_sync_,
+                   "resize",
+                   static_cast<int32>(window_.width),
+                   static_cast<int32>(window_.height));
+    }
   } else {
     memset(&window_, 0, sizeof(window_));
   }
 
   return error;
 }
 
 int16 GPUPluginObject::HandleEvent(NPEvent* event) {
   return 0;
 }
@@ skipping 64 matching lines @@
       status_ = kInitializationSuccessful;
       return command_buffer_;
     }
   }
 
   return NPObjectPointer<CommandBuffer>();
 }
 
 }  // namespace gpu_plugin
 }  // namespace o3d