pepper: Use the RenderThread's shared context as the parent context.

webkit/plugins/ppapi/ppapi_plugin_instance.cc

Index: webkit/plugins/ppapi/ppapi_plugin_instance.cc
diff --git a/webkit/plugins/ppapi/ppapi_plugin_instance.cc b/webkit/plugins/ppapi/ppapi_plugin_instance.cc
index b2eacb0313e385b52bf1b0515f75a03f2aaa7c0b..ea1be6d818f195d566abbb193b93372c97b7e845 100644
--- a/webkit/plugins/ppapi/ppapi_plugin_instance.cc
+++ b/webkit/plugins/ppapi/ppapi_plugin_instance.cc
@@ -1495,15 +1495,8 @@ void PluginInstance::UpdateFlashFullscreenState(bool flash_fullscreen) {
     return;
   }
 
-  PPB_Graphics3D_Impl* graphics_3d  = bound_graphics_3d_.get();
-  if (graphics_3d) {
-    if (flash_fullscreen) {
-      fullscreen_container_->ReparentContext(graphics_3d->platform_context());
-    } else {
-      delegate_->ReparentContext(graphics_3d->platform_context());
-    }
+  if (bound_graphics_3d_)
     UpdateLayer();
-  }
 
   bool old_plugin_focus = PluginHasFocus();
   flash_fullscreen_ = flash_fullscreen;