Update IDL to 1847

modules/mediasource/SourceBuffer.idl

Index: modules/mediasource/SourceBuffer.idl
diff --git a/modules/mediasource/SourceBuffer.idl b/modules/mediasource/SourceBuffer.idl
index e2712bdb9ad31a46fb5bdac9d676e24e60ff0b98..1272771cac3f980fe823627b57048461783bc8d8 100644
--- a/modules/mediasource/SourceBuffer.idl
+++ b/modules/mediasource/SourceBuffer.idl
@@ -28,12 +28,21 @@
  * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
  */
 
+enum AppendMode {
+    "segments",
+    "sequence"
+};
+
 [
     NoInterfaceObject,
     ActiveDOMObject,
     RuntimeEnabled=MediaSource
 ] interface SourceBuffer : EventTarget {
 
+    // Gets or sets the AppendMode.
+    // FIXME: Remove MediaSourceExperimental once mode attribute is implemented and stabilized. See http://crbug.com/249422.
+    [RaisesException=Setter, RuntimeEnabled=MediaSourceExperimental] attribute AppendMode mode;
+
     readonly attribute boolean updating;
 
     // Returns the time ranges buffered.