Enhance WebMediaPlayer::buffered() to account for evicted ranges.

media/blink/webmediaplayer_impl.cc

 // Copyright 2013 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.
 
 #include "media/blink/webmediaplayer_impl.h"
 
 #include <algorithm>
 #include <limits>
 #include <string>
 #include <vector>
@@ skipping 460 matching lines @@
 }
 
 blink::WebTimeRanges WebMediaPlayerImpl::buffered() const {
   DCHECK(main_task_runner_->BelongsToCurrentThread());
 
   Ranges<base::TimeDelta> buffered_time_ranges =
       pipeline_.GetBufferedTimeRanges();
 
   const base::TimeDelta duration = pipeline_.GetMediaDuration();
   if (duration != kInfiniteDuration()) {
-    buffered_data_source_host_.AddBufferedTimeRanges(
-        &buffered_time_ranges, duration);
+    // Demuxed ranges are not useful for a streaming resource, since we can't
+    // actually seek to those points unless they're cached.  Instead report
+    // buffered() based on the lowest cached byte range.
+    //
+    // Technically we could do this for non-streaming resources too since we're
+    // caching the same amount for them, but the returned range will be shown on
+    // the controls and historically there's been outcry when gaps are shown.
+    if (data_source_ && data_source_->IsStreaming()) {
+      Ranges<base::TimeDelta> cached_ranges;
+      buffered_data_source_host_.AddBufferedTimeRanges(&cached_ranges,
+                                                       duration);
+      buffered_time_ranges =
+          buffered_time_ranges.IntersectionWith(cached_ranges);
+    } else {
+      buffered_data_source_host_.AddBufferedTimeRanges(&buffered_time_ranges,
+                                                       duration);
+    }
   }
+
   return ConvertToWebTimeRanges(buffered_time_ranges);
 }
 
 double WebMediaPlayerImpl::maxTimeSeekable() const {
   DCHECK(main_task_runner_->BelongsToCurrentThread());
 
   // If we haven't even gotten to ReadyStateHaveMetadata yet then just
   // return 0 so that the seekable range is empty.
   if (ready_state_ < WebMediaPlayer::ReadyStateHaveMetadata)
     return 0.0;
@@ skipping 535 matching lines @@
   compositor_task_runner_->PostTask(FROM_HERE,
                                     base::Bind(&GetCurrentFrameAndSignal,
                                                base::Unretained(compositor_),
                                                &video_frame,
                                                &event));
   event.Wait();
   return video_frame;
 }
 
 }  // namespace media