Use stopped_on_render_loop_ to prevent further work from executing in BufferedDataSource.

Previously we were using it as a DCHECK but we would fail gracefully.  Now that stopped_on_render_loop_ is set via Abort() (i.e., catastrophic failure), we need to use it as a singal to make sure all work on the render loop does indeed stop.

BUG=16751
TEST=http/tests/media should stop crashing

Review URL: http://codereview.chromium.org/5603004

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@68363 0039d316-1c4b-4281-b951-d872f2087c98

2 files changed, 5 insertions, 17 deletions

diff --git a/webkit/glue/media/buffered_data_source.cc b/webkit/glue/media/buffered_data_source.cc
index c864767..2091cc9 100644
--- a/webkit/glue/media/buffered_data_source.cc
+++ b/webkit/glue/media/buffered_data_source.cc
@@ -671,7 +671,8 @@ void BufferedDataSource::Abort() {
 void BufferedDataSource::InitializeTask() {
   DCHECK(MessageLoop::current() == render_loop_);
   DCHECK(!loader_.get());
-  DCHECK(!stopped_on_render_loop_);
+  if (stopped_on_render_loop_)
+    return;
 
   // Kick starts the watch dog task that will handle connection timeout.
   // We run the watch dog 2 times faster the actual timeout so as to catch
@@ -706,11 +707,6 @@ void BufferedDataSource::ReadTask(
      int64 position, int read_size, uint8* buffer,
      media::DataSource::ReadCallback* read_callback) {
   DCHECK(MessageLoop::current() == render_loop_);
-
-  // If CleanupTask() was executed we should return immediately. We check this
-  // variable to prevent doing any actual work after clean up was done. We do
-  // not check |stop_signal_received_| because anything use of it has to be
-  // within |lock_| which is not desirable.
   if (stopped_on_render_loop_)
     return;
 
@@ -731,8 +727,6 @@ void BufferedDataSource::ReadTask(
 
 void BufferedDataSource::CleanupTask() {
   DCHECK(MessageLoop::current() == render_loop_);
-
-  // If we have already stopped, do nothing.
   if (stopped_on_render_loop_)
     return;
 
@@ -757,13 +751,6 @@ void BufferedDataSource::CleanupTask() {
 
 void BufferedDataSource::RestartLoadingTask() {
   DCHECK(MessageLoop::current() == render_loop_);
-
-  // This variable is set in CleanupTask(). We check this and do an early
-  // return. The sequence of actions which enable this conditions is:
-  // 1. Stop() is called from the pipeline.
-  // 2. ReadCallback() is called from the resource loader.
-  // 3. CleanupTask() is executed.
-  // 4. RestartLoadingTask() is executed.
   if (stopped_on_render_loop_)
     return;
 
@@ -780,7 +767,8 @@ void BufferedDataSource::RestartLoadingTask() {
 
 void BufferedDataSource::WatchDogTask() {
   DCHECK(MessageLoop::current() == render_loop_);
-  DCHECK(!stopped_on_render_loop_);
+  if (stopped_on_render_loop_)
+    return;
 
   // We only care if there is an active read request.
   if (!read_callback_.get())
diff --git a/webkit/glue/media/buffered_data_source.h b/webkit/glue/media/buffered_data_source.h
index 7218390..8f00460 100644
--- a/webkit/glue/media/buffered_data_source.h
+++ b/webkit/glue/media/buffered_data_source.h
@@ -384,7 +384,7 @@ class BufferedDataSource : public WebDataSource {
   bool stop_signal_received_;
 
   // This variable is set by CleanupTask() that indicates this object is stopped
-  // on the render thread.
+  // on the render thread and work should no longer progress.
   bool stopped_on_render_loop_;
 
   // This variable is true when we are in a paused state and false when we