Prevent Client::Tick() from causing reentrancy in the plugin on Mac OS X....

plugin/mac/plugin_mac.mm

 /*
  * Copyright 2009, Google Inc.
  * All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions are
  * met:
  *
  *     * Redistributions of source code must retain the above copyright
  * notice, this list of conditions and the following disclaimer.
@@ skipping 219 matching lines @@
   }
 }
 
 void RenderTimer::TimerCallback(CFRunLoopTimerRef timer, void* info) {
   HANDLE_CRASHES;
   int instance_count = instances_.size();
   for (int i = 0; i < instance_count; ++i) {
     NPP instance = instances_[i];
     PluginObject* obj = static_cast<PluginObject*>(instance->pdata);
 
-    // RenderClient() may cause events to be processed, leading to
-    // reentrant calling of this code. Detect and avoid this case.
-    if (obj->client()->IsRendering()) {
+    // RenderClient() and Tick() may cause events to be processed,
+    // leading to reentrant calling of this code. Detect and avoid
+    // this case.
+    if (obj->client()->IsRendering() || obj->client()->IsTicking()) {
       continue;
     }
 
     bool in_fullscreen = obj->GetFullscreenMacWindow();
 
     if (obj->drawing_model_ == NPDrawingModelCoreAnimation &&
         !in_fullscreen) {
       O3DLayer* o3dLayer = static_cast<O3DLayer*>(obj->gl_layer_);
       if (o3dLayer) {
         obj->client()->Tick();
@@ skipping 432 matching lines @@
 
 void PluginObject::SetMacCGLContext(CGLContextObj context) {
   mac_cgl_context_ = context;
   if (renderer_) {
     ((o3d::RendererGL*) renderer_)->set_mac_cgl_context(context);
   }
 }
 
 }  // namespace glue
 }  // namespace o3d