Revert 71334 - Fix Pepper URL Loader callbacks.

[Not applying the "obvious" fix, since it might lead to callbacks being called
incorrectly.]

Add some tests (for aborting calls).

BUG=none
TEST=ppapi_tests

Review URL: http://codereview.chromium.org/6220006

TBR=viettrungluu@chromium.org,jam@chromium.org,brettw@chromium.org
Review URL: http://codereview.chromium.org/6254003

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@71400 0039d316-1c4b-4281-b951-d872f2087c98

2 files changed, 38 insertions, 67 deletions

diff --git a/webkit/plugins/ppapi/ppb_url_loader_impl.cc b/webkit/plugins/ppapi/ppb_url_loader_impl.cc
index fba1b8c..14b91f8 100644
--- a/webkit/plugins/ppapi/ppb_url_loader_impl.cc
+++ b/webkit/plugins/ppapi/ppb_url_loader_impl.cc
@@ -1,4 +1,4 @@
-// Copyright (c) 2011 The Chromium Authors. All rights reserved.
+// Copyright (c) 2010 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.
 
@@ -21,7 +21,6 @@
 #include "third_party/WebKit/WebKit/chromium/public/WebURLResponse.h"
 #include "webkit/appcache/web_application_cache_host_impl.h"
 #include "webkit/plugins/ppapi/common.h"
-#include "webkit/plugins/ppapi/plugin_module.h"
 #include "webkit/plugins/ppapi/ppapi_plugin_instance.h"
 #include "webkit/plugins/ppapi/ppb_url_request_info_impl.h"
 #include "webkit/plugins/ppapi/ppb_url_response_info_impl.h"
@@ -233,19 +232,19 @@ PPB_URLLoader_Impl* PPB_URLLoader_Impl::AsPPB_URLLoader_Impl() {
 
 int32_t PPB_URLLoader_Impl::Open(PPB_URLRequestInfo_Impl* request,
                                  PP_CompletionCallback callback) {
-  int32_t rv = ValidateCallback(callback);
-  if (rv != PP_OK)
-    return rv;
-
   if (loader_.get())
     return PP_ERROR_INPROGRESS;
 
+  // We only support non-blocking calls.
+  if (!callback.func)
+    return PP_ERROR_BADARGUMENT;
+
   WebFrame* frame = GetFrame(instance_);
   if (!frame)
     return PP_ERROR_FAILED;
   WebURLRequest web_request(request->ToWebURLRequest(frame));
 
-  rv = CanRequest(frame, web_request.url());
+  int32_t rv = CanRequest(frame, web_request.url());
   if (rv != PP_OK)
     return rv;
 
@@ -264,25 +263,28 @@ int32_t PPB_URLLoader_Impl::Open(PPB_URLRequestInfo_Impl* request,
   loader_->loadAsynchronously(web_request, this);
 
   request_info_ = scoped_refptr<PPB_URLRequestInfo_Impl>(request);
+  pending_callback_ = callback;
 
   // Notify completion when we receive a redirect or response headers.
-  RegisterCallback(callback);
   return PP_ERROR_WOULDBLOCK;
 }
 
 int32_t PPB_URLLoader_Impl::FollowRedirect(PP_CompletionCallback callback) {
-  int32_t rv = ValidateCallback(callback);
-  if (rv != PP_OK)
-    return rv;
+  if (pending_callback_.func)
+    return PP_ERROR_INPROGRESS;
+
+  // We only support non-blocking calls.
+  if (!callback.func)
+    return PP_ERROR_BADARGUMENT;
 
   WebURL redirect_url = GURL(response_info_->redirect_url());
 
-  rv = CanRequest(GetFrame(instance_), redirect_url);
+  int32_t rv = CanRequest(GetFrame(instance_), redirect_url);
   if (rv != PP_OK)
     return rv;
 
+  pending_callback_ = callback;
   loader_->setDefersLoading(false);  // Allow the redirect to continue.
-  RegisterCallback(callback);
   return PP_ERROR_WOULDBLOCK;
 }
 
@@ -314,13 +316,16 @@ bool PPB_URLLoader_Impl::GetDownloadProgress(
 int32_t PPB_URLLoader_Impl::ReadResponseBody(char* buffer,
                                              int32_t bytes_to_read,
                                              PP_CompletionCallback callback) {
-  int32_t rv = ValidateCallback(callback);
-  if (rv != PP_OK)
-    return rv;
   if (!response_info_ || response_info_->body())
     return PP_ERROR_FAILED;
   if (bytes_to_read <= 0 || !buffer)
     return PP_ERROR_BADARGUMENT;
+  if (pending_callback_.func)
+    return PP_ERROR_INPROGRESS;
+
+  // We only support non-blocking calls.
+  if (!callback.func)
+    return PP_ERROR_BADARGUMENT;
 
   user_buffer_ = buffer;
   user_buffer_size_ = bytes_to_read;
@@ -335,24 +340,23 @@ int32_t PPB_URLLoader_Impl::ReadResponseBody(char* buffer,
     return done_status_;
   }
 
-  RegisterCallback(callback);
+  pending_callback_ = callback;
   return PP_ERROR_WOULDBLOCK;
 }
 
 int32_t PPB_URLLoader_Impl::FinishStreamingToFile(
     PP_CompletionCallback callback) {
-  int32_t rv = ValidateCallback(callback);
-  if (rv != PP_OK)
-    return rv;
   if (!response_info_ || !response_info_->body())
     return PP_ERROR_FAILED;
+  if (pending_callback_.func)
+    return PP_ERROR_INPROGRESS;
 
   // We may have already reached EOF.
   if (done_status_ != PP_ERROR_WOULDBLOCK)
     return done_status_;
 
   // Wait for didFinishLoading / didFail.
-  RegisterCallback(callback);
+  pending_callback_ = callback;
   return PP_ERROR_WOULDBLOCK;
 }
 
@@ -363,8 +367,6 @@ void PPB_URLLoader_Impl::Close() {
     WebFrame* frame = instance_->container()->element().document().frame();
     frame->stopLoading();
   }
-  // TODO(viettrungluu): Check what happens to the callback (probably the
-  // wrong thing). May need to post abort here. crbug.com/69457
 }
 
 void PPB_URLLoader_Impl::GrantUniversalAccess() {
@@ -429,7 +431,7 @@ void PPB_URLLoader_Impl::didReceiveData(WebURLLoader* loader,
   if (user_buffer_) {
     RunCallback(FillUserBuffer());
   } else {
-    DCHECK(!pending_callback_.get() || pending_callback_->completed());
+    DCHECK(!pending_callback_.func);
   }
 }
 
@@ -480,31 +482,13 @@ void PPB_URLLoader_Impl::InstanceDestroyed(PluginInstance* instance) {
   // goes out of scope.
 }
 
-int32_t PPB_URLLoader_Impl::ValidateCallback(PP_CompletionCallback callback) {
-  // We only support non-blocking calls.
-  if (!callback.func)
-    return PP_ERROR_BADARGUMENT;
-
-  if (pending_callback_.get() && !pending_callback_->completed())
-    return PP_ERROR_INPROGRESS;
-
-  return PP_OK;
-}
-
-void PPB_URLLoader_Impl::RegisterCallback(PP_CompletionCallback callback) {
-  DCHECK(callback.func);
-  DCHECK(!pending_callback_.get() || pending_callback_->completed());
-
-  PP_Resource resource_id = GetReferenceNoAddRef();
-  CHECK(resource_id);
-  pending_callback_ = new TrackedCompletionCallback(
-      module()->GetCallbackTracker(), resource_id, callback);
-}
-
 void PPB_URLLoader_Impl::RunCallback(int32_t result) {
-  scoped_refptr<TrackedCompletionCallback> callback;
-  callback.swap(pending_callback_);
-  callback->Run(result);  // Will complete abortively if necessary.
+  if (!pending_callback_.func)
+    return;
+
+  PP_CompletionCallback callback = {0};
+  std::swap(callback, pending_callback_);
+  PP_RunCompletionCallback(&callback, result);
 }
 
 size_t PPB_URLLoader_Impl::FillUserBuffer() {
diff --git a/webkit/plugins/ppapi/ppb_url_loader_impl.h b/webkit/plugins/ppapi/ppb_url_loader_impl.h
index 4a3d72e..6b05adc 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) 2011 The Chromium Authors. All rights reserved.
+// Copyright (c) 2010 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.
 
@@ -7,12 +7,10 @@
 
 #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"
 
@@ -91,17 +89,7 @@ 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.
@@ -122,11 +110,10 @@ 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
@@ -135,7 +122,7 @@ 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_;
-  scoped_refptr<TrackedCompletionCallback> pending_callback_;
+  PP_CompletionCallback pending_callback_;
   std::deque<char> buffer_;
   int64_t bytes_sent_;
   int64_t total_bytes_to_be_sent_;