Fix Pepper URL Loader callbacks.

webkit/plugins/ppapi/ppb_url_loader_impl.h

Index: webkit/plugins/ppapi/ppb_url_loader_impl.h
diff --git a/webkit/plugins/ppapi/ppb_url_loader_impl.h b/webkit/plugins/ppapi/ppb_url_loader_impl.h
index 6b05adc99bfedbdb510289216f5e605c409b64dd..0f26cfc6c7d8300f0fdb647feaa829adb568cd4c 100644
--- a/webkit/plugins/ppapi/ppb_url_loader_impl.h
+++ b/webkit/plugins/ppapi/ppb_url_loader_impl.h
@@ -1,4 +1,4 @@
-// Copyright (c) 2010 The Chromium Authors. All rights reserved.
+// Copyright (c) 2011 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.
 
@@ -7,10 +7,12 @@
 
 #include <deque>
 
+#include "base/ref_counted.h"
 #include "base/scoped_ptr.h"
 #include "ppapi/c/pp_completion_callback.h"
 #include "ppapi/c/trusted/ppb_url_loader_trusted.h"
 #include "third_party/WebKit/WebKit/chromium/public/WebURLLoaderClient.h"
+#include "webkit/plugins/ppapi/callbacks.h"
 #include "webkit/plugins/ppapi/ppapi_plugin_instance.h"
 #include "webkit/plugins/ppapi/resource.h"
 
@@ -89,7 +91,17 @@ class PPB_URLLoader_Impl : public Resource,
   PPB_URLResponseInfo_Impl* response_info() const { return response_info_; }
 
  private:
+  // Check that |callback| is valid (only non-blocking operation is supported)
+  // and that no callback is already pending. Returns |PP_OK| if okay, else
+  // |PP_ERROR_...| to be returned to the plugin.
+  int32_t ValidateCallback(PP_CompletionCallback callback);
+
+  // Sets up |callback| as the pending callback. This should only be called once
+  // it is certain that |PP_ERROR_WOULDBLOCK| will be returned.
+  void RegisterCallback(PP_CompletionCallback callback);
+
   void RunCallback(int32_t result);
+
   size_t FillUserBuffer();
 
   // Converts a WebURLResponse to a URLResponseInfo and saves it.
@@ -110,10 +122,11 @@ class PPB_URLLoader_Impl : public Resource,
   bool RecordDownloadProgress() const;
   bool RecordUploadProgress() const;
 
-  // This will be NULL if the instance has been deleted but this PPB_URLLoader_Impl was
-  // somehow leaked. In general, you should not need to check this for NULL.
-  // However, if you see a NULL pointer crash, that means somebody is holding
-  // a reference to this object longer than the PluginInstance's lifetime.
+  // This will be NULL if the instance has been deleted but this
+  // PPB_URLLoader_Impl was somehow leaked. In general, you should not need to
+  // check this for NULL. However, if you see a NULL pointer crash, that means
+  // somebody is holding a reference to this object longer than the
+  // PluginInstance's lifetime.
   PluginInstance* instance_;
 
   // If true, then the plugin instance is a full-frame plugin and we're just
@@ -122,7 +135,7 @@ class PPB_URLLoader_Impl : public Resource,
   scoped_ptr<WebKit::WebURLLoader> loader_;
   scoped_refptr<PPB_URLRequestInfo_Impl> request_info_;
   scoped_refptr<PPB_URLResponseInfo_Impl> response_info_;
-  PP_CompletionCallback pending_callback_;
+  scoped_refptr<TrackedCompletionCallback> pending_callback_;
   std::deque<char> buffer_;
   int64_t bytes_sent_;
   int64_t total_bytes_to_be_sent_;
@@ -134,6 +147,8 @@ class PPB_URLLoader_Impl : public Resource,
 
   bool has_universal_access_;
 
+  // TODO(viettrungluu): does the status callback need to be tracked? (and have

[brettw, 2011/01/13 03:08:30]

Extra tracking here shouldn't be necessary. This just allows the URLLoader to
call into the proxy without a direct dependency, and the proxy function should
handle everything.

+  // semantics with respect to resource deletion verified?)
   PP_URLLoaderTrusted_StatusCallback status_callback_;
 
   DISALLOW_COPY_AND_ASSIGN(PPB_URLLoader_Impl);