[Downloads] Deprecate incorrect metrics.

content/browser/download/download_request_core.cc

Index: content/browser/download/download_request_core.cc
diff --git a/content/browser/download/download_request_core.cc b/content/browser/download/download_request_core.cc
index 8af8fe2368edf52b0e83f5b6327c2b57fb1f0032..b5c504baa06ed3f21ab3dc0619a719d8fc04218c 100644
--- a/content/browser/download/download_request_core.cc
+++ b/content/browser/download/download_request_core.cc
@@ -202,7 +202,6 @@ DownloadRequestCore::DownloadRequestCore(net::URLRequest* request,
     : delegate_(delegate),
       request_(request),
       download_id_(DownloadItem::kInvalidId),
-      last_buffer_size_(0),
       bytes_read_(0),
       pause_count_(0),
       was_deferred_(false),
@@ -234,9 +233,6 @@ DownloadRequestCore::~DownloadRequestCore() {
   // Remove output stream callback if a stream exists.
   if (stream_writer_)
     stream_writer_->RegisterCallback(base::Closure());
-
-  UMA_HISTOGRAM_TIMES("SB2.DownloadDuration",
-                      base::TimeTicks::Now() - download_start_time_);
 }
 
 std::unique_ptr<DownloadCreateInfo>
@@ -366,7 +362,6 @@ bool DownloadRequestCore::OnWillRead(scoped_refptr<net::IOBuffer>* buf,
   DCHECK(!read_buffer_.get());
 
   *buf_size = min_size < 0 ? kReadBufSize : min_size;
-  last_buffer_size_ = *buf_size;
   read_buffer_ = new net::IOBuffer(*buf_size);
   *buf = read_buffer_.get();
   return true;
@@ -377,20 +372,6 @@ bool DownloadRequestCore::OnReadCompleted(int bytes_read, bool* defer) {
   DCHECK_CURRENTLY_ON(BrowserThread::IO);
   DCHECK(read_buffer_.get());
 
-  base::TimeTicks now(base::TimeTicks::Now());
-  if (!last_read_time_.is_null()) {
-    double seconds_since_last_read = (now - last_read_time_).InSecondsF();
-    if (now == last_read_time_)
-      // Use 1/10 ms as a "very small number" so that we avoid
-      // divide-by-zero error and still record a very high potential bandwidth.
-      seconds_since_last_read = 0.00001;
-
-    double actual_bandwidth = (bytes_read) / seconds_since_last_read;
-    double potential_bandwidth = last_buffer_size_ / seconds_since_last_read;
-    RecordBandwidth(actual_bandwidth, potential_bandwidth);
-  }
-  last_read_time_ = now;
-
   if (!bytes_read)
     return true;
   bytes_read_ += bytes_read;
@@ -401,7 +382,7 @@ bool DownloadRequestCore::OnReadCompleted(int bytes_read, bool* defer) {
   if (!stream_writer_->Write(read_buffer_, bytes_read)) {
     PauseRequest();
     *defer = was_deferred_ = true;
-    last_stream_pause_time_ = now;
+    last_stream_pause_time_ = base::TimeTicks::Now();
   }
 
   read_buffer_ = NULL;  // Drop our reference.