Add a simple, safe gain PostProcessor.

chromecast/media/cma/backend/alsa/post_processing_pipeline_parser.h

 // Copyright 2017 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 CHROMECAST_MEDIA_CMA_BACKEND_ALSA_POST_PROCESSING_PIPELINE_PARSER_H_
 #define CHROMECAST_MEDIA_CMA_BACKEND_ALSA_POST_PROCESSING_PIPELINE_PARSER_H_
 
 #include <memory>
 #include <string>
 #include <unordered_set>
@@ skipping 37 matching lines @@
   explicit PostProcessingPipelineParser(const std::string& json = "");
   ~PostProcessingPipelineParser();
 
   std::vector<StreamPipelineDescriptor> GetStreamPipelines();
 
   // Gets the list of processors for the mix/linearize stages.
   // Same format as StreamPipelineDescriptor.pipeline
   const base::ListValue* GetMixPipeline();
   const base::ListValue* GetLinearizePipeline();
 
-  static std::string GetFilePath();
-
  private:
   const base::ListValue* GetPipelineByKey(const std::string& key);
 
   std::unique_ptr<base::DictionaryValue> config_dict_;
   const base::DictionaryValue* postprocessor_config_;
 
   DISALLOW_COPY_AND_ASSIGN(PostProcessingPipelineParser);
 };
 
 }  // namepsace media
 }  // namespace chromecast
 
 #endif  // CHROMECAST_MEDIA_CMA_BACKEND_ALSA_POST_PROCESSING_PIPELINE_PARSER_H_