Convert URLLoader to the new proxy design

ppapi/api/ppp_instance.idl

Index: ppapi/api/ppp_instance.idl
diff --git a/ppapi/api/ppp_instance.idl b/ppapi/api/ppp_instance.idl
index a5026ae23a762cacf0e3b0630a61eb169510ed61..68d9080e2acaffb5ca65695c7f61af5a8716ad33 100644
--- a/ppapi/api/ppp_instance.idl
+++ b/ppapi/api/ppp_instance.idl
@@ -207,11 +207,12 @@ interface PPP_Instance {
 
   /**
    * HandleDocumentLoad() is called after initialize for a full-frame
-   * module that was instantiated based on the MIME type of a DOMWindow
+   * instance that was instantiated based on the MIME type of a DOMWindow
    * navigation. This situation only applies to modules that are pre-registered
    * to handle certain MIME types. If you haven't specifically registered to
-   * handle a MIME type or aren't positive this applies to you, your
-   * implementation of this function can just return <code>PP_FALSE</code>.
+   * handle a MIME type or aren't positive this applies to you (Native Client
+   * plugins can't register for MIME type handling), your implementation of
+   * this function can just return <code>PP_FALSE</code>.
    *
    * The given <code>url_loader</code> corresponds to a
    * <code>PPB_URLLoader</code> instance that is already opened. Its response
@@ -224,13 +225,9 @@ interface PPP_Instance {
    * data. In response to this method, the module should call
    * ReadResponseBody() to read the incoming data.
    *
-   * @param[in] instance A <code>PP_Instance</code> identifying the instance
-   * that should do the load.
-   *
-   * @param[in] url_loader An open <code>PPB_URLLoader</code> instance.
-   *
    * @return <code>PP_TRUE</code> if the data was handled,
-   * <code>PP_FALSE</code> otherwise.
+   * <code>PP_FALSE</code> otherwise. If you return false, the load will be
+   * canceled for you.
    */
   PP_Bool HandleDocumentLoad(
       /* A PP_Instance identifying one instance of a module. */