Switch base::Value typemapping to be by value instead of by unique_ptr.

media/base/video_frame_metadata.cc

 // Copyright 2015 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/base/video_frame_metadata.h"
 
 #include <stdint.h>
 #include <utility>
 
 #include "base/logging.h"
@@ skipping 133 matching lines @@
   if (!dictionary_.GetWithoutPathExpansion(ToInternalKey(key), &result))
     return nullptr;
   return result;
 }
 
 bool VideoFrameMetadata::IsTrue(Key key) const {
   bool value = false;
   return GetBoolean(key, &value) && value;
 }
 
-std::unique_ptr<base::DictionaryValue> VideoFrameMetadata::CopyInternalValues()
-    const {
-  return dictionary_.CreateDeepCopy();
+const base::DictionaryValue& VideoFrameMetadata::GetInternalValues() const {
+  return dictionary_;
 }
 
 void VideoFrameMetadata::MergeInternalValuesFrom(
     const base::DictionaryValue& in) {
   dictionary_.MergeDictionary(&in);
 }
 
 void VideoFrameMetadata::MergeMetadataFrom(
     const VideoFrameMetadata* metadata_source) {
   dictionary_.MergeDictionary(&metadata_source->dictionary_);
 }
 
 const base::BinaryValue* VideoFrameMetadata::GetBinaryValue(Key key) const {
   const base::Value* internal_value = nullptr;
   if (dictionary_.GetWithoutPathExpansion(ToInternalKey(key),
                                           &internal_value) &&
       internal_value->GetType() == base::Value::Type::BINARY) {
     return internal_value;
   }
   return nullptr;
 }
 
 }  // namespace media