Split BufferedResourceLoader's network callback into separate loading state and progress callbacks.

webkit/media/buffered_resource_loader.h

Index: webkit/media/buffered_resource_loader.h
diff --git a/webkit/media/buffered_resource_loader.h b/webkit/media/buffered_resource_loader.h
index 32779413e6710890b417e3cf5534b54947ceb09d..035f9e5a8af09ebbe4065cd2dff1457a2939380d 100644
--- a/webkit/media/buffered_resource_loader.h
+++ b/webkit/media/buffered_resource_loader.h
@@ -65,6 +65,13 @@ class BufferedResourceLoader : public WebKit::WebURLLoaderClient {
     kCacheMiss,
   };
 
+  enum LoadingState {
+    kLoading,  // Actively attempting to download data.
+    kLoadingDeferred,  // Loading intentionally deferred.
+    kLoadingFinished,  // Loading finished normally; no more data will arrive.
+    kLoadingFailed,  // Loading finished abnormally; no more data will arrive.
+  };
+
   // |url| - URL for the resource to be loaded.
   // |first_byte_position| - First byte to start loading from,
   // |kPositionNotSpecified| for not specified.
@@ -84,15 +91,14 @@ class BufferedResourceLoader : public WebKit::WebURLLoaderClient {
 
   // Start the resource loading with the specified URL and range.
   //
-  // |event_cb| is called to notify the client of network activity in the
-  // following situations:
-  //   - Data was received
-  //   - Reading was suspended/resumed
-  //   - Loading completed
-  //   - Loading failed
+  // |progress_cb| is executed when additional data has arrived.
+  // |loading_cb| is executed when the loading state has changed.

[Ami GONE FROM CHROMIUM, 2012/07/09 00:25:46]

Flip order of these two lines to match the orders below.

[scherkus (not reviewing), 2012/07/09 18:53:30]

Done.

   typedef base::Callback<void(Status)> StartCB;
+  typedef base::Callback<void(LoadingState)> LoadingCB;
+  typedef base::Callback<void(int64)> ProgressCB;
   void Start(const StartCB& start_cb,
-             const base::Closure& event_cb,
+             const LoadingCB& loading_cb,
+             const ProgressCB& progress_cb,
              WebKit::WebFrame* frame);
 
   // Stops everything associated with this loader, including active URL loads
@@ -113,10 +119,6 @@ class BufferedResourceLoader : public WebKit::WebURLLoaderClient {
   void Read(int64 position, int read_size,
             uint8* buffer, const ReadCB& read_cb);
 
-  // Returns the position of the last byte buffered. Returns
-  // |kPositionNotSpecified| if such value is not available.
-  int64 GetBufferedPosition();

[Ami GONE FROM CHROMIUM, 2012/07/09 00:25:46]

hawt!

-
   // Gets the content length in bytes of the instance after this loader has been
   // started. If this value is |kPositionNotSpecified|, then content length is
   // unknown.
@@ -246,9 +248,6 @@ class BufferedResourceLoader : public WebKit::WebURLLoaderClient {
   // Done with start. Invokes the start callback and reset it.
   void DoneStart(Status status);
 
-  // Calls |event_cb_| in terms of a network event.
-  void NotifyNetworkEvent();
-
   bool HasPendingRead() { return !read_cb_.is_null(); }
 
   // Helper function that returns true if a range request was specified.
@@ -285,8 +284,12 @@ class BufferedResourceLoader : public WebKit::WebURLLoaderClient {
   int64 last_byte_position_;
   bool single_origin_;
 
-  // Closure that listens to network events.
-  base::Closure event_cb_;
+  // Executed whenever the state of resource loading has changed.
+  LoadingCB loading_cb_;

[Ami GONE FROM CHROMIUM, 2012/07/09 00:25:46]

LoadingStateChangedCB?
LoadingCB sounds to me like something that'll fire exactly once (when loading
kicks off).  But LSCCB is a mouthful...
Up to you, just wanted to flag opportunity for improved naming.

[scherkus (not reviewing), 2012/07/09 18:53:30]

It's a mouthful but I agree that LoadingCB is a bit deceptive

+
+  // Executed whenever additional data has been downloaded and reports the
+  // zero-indexed file offset of the leading buffered byte.

[Ami GONE FROM CHROMIUM, 2012/07/09 00:25:46]

s/leading/furthest/?

[scherkus (not reviewing), 2012/07/09 18:53:30]

Done.

+  ProgressCB progress_cb_;
 
   // Members used during request start.
   StartCB start_cb_;