Fire CanPlayThrough immediately for local and streaming media files

media/base/demuxer.h

Index: media/base/demuxer.h
diff --git a/media/base/demuxer.h b/media/base/demuxer.h
index a75f248844cab6d65efa415e7c065ff0ad0e2d61..972d250a094cfdbd84d275718d3b837edaa4c15c 100644
--- a/media/base/demuxer.h
+++ b/media/base/demuxer.h
@@ -61,6 +61,13 @@ class MEDIA_EXPORT Demuxer
   // approximated. Returns 0 if it is unknown.
   virtual int GetBitrate() = 0;
 
+  // Returns true if the source is from a local file or stream (such as a
+  // webcam stream), false otherwise.
+  virtual bool IsLocalSource() = 0;
+
+  // Returns true if seeking is possible; false otherwise.
+  virtual bool IsSeekable() = 0;
+
  protected:
   Demuxer();
   FilterHost* host() { return host_; }