Suppress pause-and-buffer behavior when the HTTP response won't satisfy future requests via cache.

webkit/media/buffered_resource_loader.h

 // Copyright (c) 2012 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #ifndef WEBKIT_MEDIA_BUFFERED_RESOURCE_LOADER_H_
 #define WEBKIT_MEDIA_BUFFERED_RESOURCE_LOADER_H_
 
 #include <string>
 
 #include "base/callback.h"
@@ skipping 151 matching lines @@
       WebKit::WebURLLoader* loader,
       double finishTime);
   virtual void didFail(
       WebKit::WebURLLoader* loader,
       const WebKit::WebURLError&);
 
   // Returns true if the media resource has a single origin, false otherwise.
   // Only valid to call after Start() has completed.
   bool HasSingleOrigin() const;
 
-  // Sets the defer strategy to the given value.
+  // Sets the defer strategy to the given value unless it seems unwise.
+  // Specifically downgrade kNeverDefer to kThresholdDefer if we know the
+  // current response will not be used to satisfy future requests (the cache
+  // won't help us).
   void UpdateDeferStrategy(DeferStrategy strategy);
 
   // Sets the playback rate to the given value and updates buffer window
   // accordingly.
   void SetPlaybackRate(float playback_rate);
 
   // Sets the bitrate to the given value and updates buffer window
   // accordingly.
   void SetBitrate(int bitrate);
 
@@ skipping 77 matching lines @@
   // Keeps track of an active WebURLLoader and associated state.
   scoped_ptr<ActiveLoader> active_loader_;
 
   // Tracks if |active_loader_| failed. If so, then all calls to Read() will
   // fail.
   bool loader_failed_;
 
   // Current buffering algorithm in place for resource loading.
   DeferStrategy defer_strategy_;
 
+  // True if the currently-reading response might be used to satisfy a future
+  // request from the cache.
+  bool might_be_reused_from_cache_in_future_;
+
   // True if Range header is supported.
   bool range_supported_;
 
   // Forward capacity to reset to after an extension.
   size_t saved_forward_capacity_;
 
   GURL url_;
   int64 first_byte_position_;
   int64 last_byte_position_;
   bool single_origin_;
@@ skipping 29 matching lines @@
   float playback_rate_;
 
   scoped_refptr<media::MediaLog> media_log_;
 
   DISALLOW_COPY_AND_ASSIGN(BufferedResourceLoader);
 };
 
 }  // namespace webkit_media
 
 #endif  // WEBKIT_MEDIA_BUFFERED_RESOURCE_LOADER_H_