Fix last_range != range_for_next_append_ DCHECK in SourceBufferStream.

media/filters/source_buffer_stream.cc

 // 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.
 
 #include "media/filters/source_buffer_stream.h"
 
 #include <algorithm>
 #include <map>
 
 #include "base/bind.h"
@@ skipping 373 matching lines @@
   RangeList::iterator last_range = range_for_next_append_;
   range_for_next_append_ = FindExistingRangeFor(media_segment_start_time);
 
   // Only reset |last_appended_buffer_timestamp_| if this new media segment is
   // not adjacent to the previous media segment appended to the stream.
   if (range_for_next_append_ == ranges_.end() ||
       !AreAdjacentInSequence(last_appended_buffer_timestamp_,
                              media_segment_start_time)) {
     last_appended_buffer_timestamp_ = kNoTimestamp();
     last_appended_buffer_is_keyframe_ = false;
-  } else {
+  } else if (last_range != ranges_.end()) {
     DCHECK(last_range == range_for_next_append_);
   }
 }
 
 bool SourceBufferStream::Append(
     const SourceBufferStream::BufferQueue& buffers) {
   TRACE_EVENT2("mse", "SourceBufferStream::Append",
                "stream type", GetStreamTypeName(),
                "buffers to append", buffers.size());
 
@@ skipping 1545 matching lines @@
   return ComputeFudgeRoom(GetApproximateDuration());
 }
 
 base::TimeDelta SourceBufferRange::GetApproximateDuration() const {
   base::TimeDelta max_interbuffer_distance = interbuffer_distance_cb_.Run();
   DCHECK(max_interbuffer_distance != kNoTimestamp());
   return max_interbuffer_distance;
 }
 
 }  // namespace media