Tie multibuffers to URLs

media/blink/multibuffer.h

Index: media/blink/multibuffer.h
diff --git a/media/blink/multibuffer.h b/media/blink/multibuffer.h
index d469d43fc146f5c6c323bb371bfc4ecdbd4853e6..e3e7fd0d1ff989e10340019da2904d95e0a9447c 100644
--- a/media/blink/multibuffer.h
+++ b/media/blink/multibuffer.h
@@ -119,9 +119,6 @@ class MEDIA_BLINK_EXPORT MultiBuffer {
     // DataBuffer.
     virtual scoped_refptr<DataBuffer> Read() = 0;
 
-    // |cb| is called every time Available() becomes true.
-    virtual void SetAvailableCallback(const base::Closure& cb) = 0;
-
     // Ask the data provider to stop giving us data.
     // It's ok if the effect is not immediate.
     virtual void SetDeferred(bool deferred) = 0;
@@ -229,8 +226,8 @@ class MEDIA_BLINK_EXPORT MultiBuffer {
   // not call it anymore.
   scoped_ptr<DataProvider> RemoveProvider(DataProvider* provider);
 
-  // Add a writer to this cache. Cache takes ownership and
-  // may choose to destroy it.
+  // Add a writer to this cache. Cache takes ownership, and may
+  // destroy |provider| later. (Not during this call.)
   void AddProvider(scoped_ptr<DataProvider> provider);
 
   // Transfer all data from |other| to this.
@@ -240,12 +237,18 @@ class MEDIA_BLINK_EXPORT MultiBuffer {
   const DataMap& map() const { return data_; }
   int32_t block_size_shift() const { return block_size_shift_; }
 
+  // Callback which notifies us that a data provider has
+  // some data for us. Also called when it might be apprperiate
+  // for a provider in a deferred state to wake up.
+  void DataProviderEvent(DataProvider* provider);

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

In media/ callbacks are often called OnXxx, not sure whether OnDataProviderEvent
would make sense. Also "event" is vague. Can we make it more clear?
OnDataAvailable doesn't cover the wake up case... 

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

OnDataProviderEvent() seems ok, can't think of something better right now...
Event here is used in the same sense as "event loop", but I'm not sure how to
make that clear either.

DataProviderHandler() ?
OnDataProviderNeedsToDoSomething() ?
DataProviderCallback() ?

+
  protected:
   // Create a new writer at |pos| and return it.
   // Users needs to implemement this method.
   virtual DataProvider* CreateWriter(const BlockId& pos) = 0;

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

Who owns the created Writer? If the caller owns it, return a scoped_ptr?

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

Done.

 
   virtual bool RangeSupported() const = 0;
+  virtual void OnEmpty();
 
  private:
   // For testing.
@@ -276,11 +279,6 @@ class MEDIA_BLINK_EXPORT MultiBuffer {
   void NotifyAvailableRange(const Interval<MultiBufferBlockId>& observer_range,
                             const Interval<MultiBufferBlockId>& new_range);
 
-  // Callback which notifies us that a data provider has
-  // some data for us. Also called when it might be apprperiate
-  // for a provider in a deferred state to wake up.
-  void DataProviderEvent(DataProvider* provider);
-
   // Max number of blocks.
   int64_t max_size_;