Fold RestartLoadingTask() into ReadCallback() as the method is called on the render thread.

This is the cache miss equivalent of r118386. We were unnecessarily posting a task to restart the HTTP request on a cache miss. On pages with heavy activity this can delay the load until the task can get executed.

BUG=none
TEST=none


Review URL: https://chromiumcodereview.appspot.com/10700125

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@146281 0039d316-1c4b-4281-b951-d872f2087c98

webkit/media/buffered_data_source.cc

@@ -254,27 +254,6 @@ void BufferedDataSource::CleanupTask() {
   read_buffer_ = 0;
 }
 
-void BufferedDataSource::RestartLoadingTask() {
-  DCHECK(MessageLoop::current() == render_loop_);
-  if (stopped_on_render_loop_)
-    return;
-
-  {
-    // If there's no outstanding read then return early.
-    base::AutoLock auto_lock(lock_);
-    if (read_cb_.is_null())
-      return;
-  }
-
-  // Start reading from where we last left off until the end of the resource.
-  loader_.reset(CreateResourceLoader(last_read_start_, kPositionNotSpecified));
-  loader_->Start(
-      base::Bind(&BufferedDataSource::PartialReadStartCallback, this),
-      base::Bind(&BufferedDataSource::LoadingStateChangedCallback, this),
-      base::Bind(&BufferedDataSource::ProgressCallback, this),
-      frame_);
-}
-
 void BufferedDataSource::SetPlaybackRateTask(float playback_rate) {
   DCHECK(MessageLoop::current() == render_loop_);
   DCHECK(loader_.get());
@@ -437,8 +416,16 @@ void BufferedDataSource::ReadCallback(
     if (status == BufferedResourceLoader::kCacheMiss &&
         cache_miss_retries_left_ > 0) {
       cache_miss_retries_left_--;
-      render_loop_->PostTask(FROM_HERE,
-          base::Bind(&BufferedDataSource::RestartLoadingTask, this));
+
+      // Recreate a loader starting from where we last left off until the
+      // end of the resource.
+      loader_.reset(CreateResourceLoader(
+          last_read_start_, kPositionNotSpecified));
+      loader_->Start(
+          base::Bind(&BufferedDataSource::PartialReadStartCallback, this),
+          base::Bind(&BufferedDataSource::LoadingStateChangedCallback, this),
+          base::Bind(&BufferedDataSource::ProgressCallback, this),
+          frame_);
       return;
     }
 

webkit/media/buffered_data_source.h

@@ -95,14 +95,11 @@ class BufferedDataSource : public media::DataSource {
   // Task posted to perform actual reading on the render thread.
   void ReadTask(int64 position, int read_size, uint8* read_buffer);
 
-  // Task posted when Stop() is called. Stops |watch_dog_timer_| and
-  // |loader_|, reset Read() variables, and set |stopped_on_render_loop_|
-  // to signal any remaining tasks to stop.
+  // Task posted when Stop() is called. Stops |loader_|, resets Read()
+  // variables, and sets |stopped_on_render_loop_| to signal any remaining
+  // tasks to stop.
   void CleanupTask();
 
-  // Restart resource loading on render thread.
-  void RestartLoadingTask();
-
   // This task uses the current playback rate with the previous playback rate
   // to determine whether we are going from pause to play and play to pause,
   // and signals the buffered resource loader accordingly.

webkit/media/buffered_resource_loader.cc

@@ -509,8 +509,7 @@ void BufferedResourceLoader::didFinishLoading(
     return;
   }
 
-  // If there is a pending read but the request has ended, return with what
-  // we have.
+  // Don't leave read callbacks hanging around.
   if (HasPendingRead()) {
     // Try to fulfill with what is in the buffer.
     if (CanFulfillRead())
@@ -518,9 +517,6 @@ void BufferedResourceLoader::didFinishLoading(
     else
       DoneRead(kCacheMiss, 0);
   }
-
-  // There must not be any outstanding read request.
-  DCHECK(!HasPendingRead());
 }
 
 void BufferedResourceLoader::didFail(