Add SupportsConfigChanges() to DemuxerStream.

media/filters/decrypting_demuxer_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/decrypting_demuxer_stream.h"
 
 #include "base/bind.h"
 #include "base/callback_helpers.h"
 #include "base/location.h"
 #include "base/logging.h"
@@ skipping 143 matching lines @@
 
 DemuxerStream::Type DecryptingDemuxerStream::type() {
   DCHECK(state_ != kUninitialized && state_ != kDecryptorRequested) << state_;
   return demuxer_stream_->type();
 }
 
 void DecryptingDemuxerStream::EnableBitstreamConverter() {
   demuxer_stream_->EnableBitstreamConverter();
 }
 
+bool DecryptingDemuxerStream::SupportsConfigChanges() {
+  DCHECK(demuxer_stream_);

[scherkus (not reviewing), 2014/03/25 23:17:58]

we tend to avoid these DCHECK()s as null pointer dereferences have their own
built-in DCHECK-like behaviour that even works in release mode (i.e., they
crash)

(also our code would be littered with 1000s of DCHECK()s for valid pointers! the
only time we tend to use them is if the pointer isn't immediately dereferenced
[e.g., pass a pointer into a ctor that requires it to be non-null, but you only
use the pointer sometime way after the ctor completes])

+  return demuxer_stream_->SupportsConfigChanges();
+}
+
 DecryptingDemuxerStream::~DecryptingDemuxerStream() {
   DVLOG(2) << __FUNCTION__ << " : state_ = " << state_;
 }
 
 void DecryptingDemuxerStream::SetDecryptor(Decryptor* decryptor) {
   DVLOG(2) << __FUNCTION__;
   DCHECK(task_runner_->BelongsToCurrentThread());
   DCHECK_EQ(state_, kDecryptorRequested) << state_;
   DCHECK(!init_cb_.is_null());
   DCHECK(!set_decryptor_ready_cb_.is_null());
@@ skipping 212 matching lines @@
       break;
     }
 
     default:
       NOTREACHED();
       return;
   }
 }
 
 }  // namespace media