Use ByteStream in downloads system to decouple source and sink.

content/browser/download/download_net_log_parameters.cc

Index: content/browser/download/download_net_log_parameters.cc
diff --git a/content/browser/download/download_net_log_parameters.cc b/content/browser/download/download_net_log_parameters.cc
index 8211cfc966ebde8827a8a2accf23cfc7d7effc46..6051823ffbd6e12ebe9d06919c2cc104003939d1 100644
--- a/content/browser/download/download_net_log_parameters.cc
+++ b/content/browser/download/download_net_log_parameters.cc
@@ -203,6 +203,20 @@ Value* FileOpenedParameters::ToValue() const {
   return dict;
 }
 
+FilePipeDrainedParameters::FilePipeDrainedParameters(
+    size_t pipe_size, size_t num_buffers)
+    : pipe_size_(pipe_size), num_buffers_(num_buffers) {
+}
+
+Value* FilePipeDrainedParameters::ToValue() const {
+  DictionaryValue* dict = new DictionaryValue();
+
+  dict->SetInteger("pipe_size", static_cast<int>(pipe_size_));
+  dict->SetInteger("num_buffers", static_cast<int>(num_buffers_));
+
+  return dict;
+}
+
 FileRenamedParameters::FileRenamedParameters(
     const std::string& old_filename, const std::string& new_filename)
         : old_filename_(old_filename), new_filename_(new_filename) {