Provide a safer URLLoader ReadResponseBody API

ppapi/api/ppb_url_loader.idl

Index: ppapi/api/ppb_url_loader.idl
diff --git a/ppapi/api/ppb_url_loader.idl b/ppapi/api/ppb_url_loader.idl
index ad311009e67c7e1caed6e6ce58c9a152e42e00ff..03463a6e2f058ef61c5329cc7ba9100befdb78f8 100644
--- a/ppapi/api/ppb_url_loader.idl
+++ b/ppapi/api/ppb_url_loader.idl
@@ -9,7 +9,8 @@
  */
 
 label Chrome {
-  M14 = 1.0
+  M14 = 1.0,
+  M26 = 1.1
 };
 
 /**
@@ -163,6 +164,9 @@ interface PPB_URLLoader {
    * buffer must be large enough to hold the specified number of bytes to read.
    * This function might perform a partial read.
    *
+   * ReadResponseBodyToArray() is preferred to ReadResponseBody() when doing
+   * asynchronous operations.
+   *
    * @param[in] loader A <code>PP_Resource</code> corresponding to a
    * <code>URLLoader</code>.
    * @param[in,out] buffer A pointer to the buffer for the response body.
@@ -217,5 +221,29 @@ interface PPB_URLLoader {
    */
   void Close(
       [in] PP_Resource loader);
+
+  /**
+   * ReadResponseBody() is used to read the response body. The size of the
+   * buffer must be large enough to hold the specified number of bytes to read.
+   * This function might perform a partial read.
+   *
+   * @param[in] loader A <code>PP_Resource</code> corresponding to a
+   * <code>URLLoader</code>.
+   * @param[in,out] output A <code>PP_ArrayOutput</code> to hold the output.
+   * @param[in] max_read_length The number of bytes to read.
+   * @param[in] callback A <code>PP_CompletionCallback</code> to run on
+   * asynchronous completion. The callback will run if the bytes (full or
+   * partial) are read or an error occurs asynchronously. This callback will
+   * run only if this function returns <code>PP_OK_COMPLETIONPENDING</code>.
+   *
+   * @return An int32_t containing the number of bytes read or an error code
+   * from <code>pp_errors.h</code>.
+   */
+  [version = 1.1]
+  int32_t ReadResponseBodyToArray(
+      [in] PP_Resource loader,
+      [in] int32_t max_read_length,
+      [inout] PP_ArrayOutput output,
+      [in] PP_CompletionCallback callback);
 };