Tie multibuffers to URLs

media/blink/multibuffer.cc

Index: media/blink/multibuffer.cc
diff --git a/media/blink/multibuffer.cc b/media/blink/multibuffer.cc
index 41c35825f53d179b8dab721f71a4dd7baa03b25a..7cd3bd2ee0bc744fa464f9b75b33d4937f57e604 100644
--- a/media/blink/multibuffer.cc
+++ b/media/blink/multibuffer.cc
@@ -162,8 +162,6 @@ void MultiBuffer::AddReader(const BlockId& pos, Reader* reader) {
   if (!provider) {
     DCHECK(writer_index_.find(pos) == writer_index_.end());
     provider = writer_index_[pos] = CreateWriter(pos);
-    provider->SetAvailableCallback(base::Bind(
-        &MultiBuffer::DataProviderEvent, base::Unretained(this), provider));
   }
   provider->SetDeferred(false);
 }
@@ -258,8 +256,13 @@ void MultiBuffer::ReleaseBlocks(const std::vector<MultiBufferBlockId>& blocks) {
       }
     }
   }
+  if (data_.empty()) {
+    OnEmpty();
+  }

[xhwang, 2015/11/19 23:34:17]

tiny nit: braces can be omitted here. I actually saw mixed style in this file.
Is there any special rule you are following?

[hubbe, 2015/11/20 23:24:22]

No, unfortunately I'm still all mixed up since I used to work in a group where
we required braces everywhere.

Done.

 }
 
+void MultiBuffer::OnEmpty() {}

[xhwang, 2015/11/19 23:34:17]

What's the purpose of this? Will some test class override this?

[hubbe, 2015/11/20 23:24:22]

Comment added in multibuffer.h
See ResourceMultiBuffer::OnEmpty in url_index.h/cc

+
 void MultiBuffer::AddProvider(scoped_ptr<DataProvider> provider) {
   // If there is already a provider in the same location, we delete it.
   DCHECK(!provider->Available());