Split a portion of BufferedResourceLoader into a separate class ActiveLoader.

ActiveLoader encapsulates an active WebURLLoader and takes care of maintaining deferred status, references to parent object, and automatic cancelation during teardown.

As a result of fixing the imbalanced reference counts to BufferedResourceLoader there were a few use-after-free bugs due to doing work after executing callbacks. The ordering has been updated to ensure that no more work is done after executing callbacks.

BUG=100914

Review URL: http://codereview.chromium.org/8667002

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@112747 0039d316-1c4b-4281-b951-d872f2087c98

1 files changed, 37 insertions, 0 deletions

diff --git a/webkit/media/active_loader.cc b/webkit/media/active_loader.cc
new file mode 100644
index 0000000..c713fe1
--- /dev/null
+++ b/webkit/media/active_loader.cc
@@ -0,0 +1,37 @@
+// 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.
+
+#include "webkit/media/active_loader.h"
+
+#include "third_party/WebKit/Source/WebKit/chromium/public/WebURLLoader.h"
+#include "webkit/media/buffered_resource_loader.h"
+
+namespace webkit_media {
+
+ActiveLoader::ActiveLoader(
+    const scoped_refptr<BufferedResourceLoader>& parent,
+    WebKit::WebURLLoader* loader)
+    : parent_(parent),
+      loader_(loader),
+      deferred_(false) {
+}
+
+ActiveLoader::~ActiveLoader() {
+  if (parent_)
+    Cancel();
+}
+
+void ActiveLoader::SetDeferred(bool deferred) {
+  deferred_ = deferred;
+  loader_->setDefersLoading(deferred);
+}
+
+void ActiveLoader::Cancel() {
+  // We only need to maintain a reference to our parent while the loader is
+  // still active. Failing to do so can result in circular refcounts.
+  loader_->cancel();
+  parent_ = NULL;
+}
+
+}  // namespace webkit_media