Call Start() from NetMetricsLogUploader.

components/metrics/net/net_metrics_log_uploader.cc

 // Copyright 2014 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 "components/metrics/net/net_metrics_log_uploader.h"
 
 #include "base/metrics/histogram.h"
 #include "components/metrics/net/compression_utils.h"
 #include "net/base/load_flags.h"
 #include "net/url_request/url_fetcher.h"
@@ skipping 37 matching lines @@
   // Tell the server that we're uploading gzipped protobufs.
   current_fetch_->SetExtraRequestHeaders("content-encoding: gzip");
 
   DCHECK(!log_hash.empty());
   current_fetch_->AddExtraRequestHeader("X-Chrome-UMA-Log-SHA1: " + log_hash);
 
   // We already drop cookies server-side, but we might as well strip them out
   // client-side as well.
   current_fetch_->SetLoadFlags(net::LOAD_DO_NOT_SAVE_COOKIES |
                                net::LOAD_DO_NOT_SEND_COOKIES);
+  current_fetch_->Start();
   return true;
 }
 
 void NetMetricsLogUploader::OnURLFetchComplete(const net::URLFetcher* source) {
   // We're not allowed to re-use the existing |URLFetcher|s, so free them here.
   // Note however that |source| is aliased to the fetcher, so we should be
   // careful not to delete it too early.
   DCHECK_EQ(current_fetch_.get(), source);
 
   int response_code = source->GetResponseCode();
   if (response_code == net::URLFetcher::RESPONSE_CODE_INVALID)
     response_code = -1;
   on_upload_complete_.Run(response_code);
   current_fetch_.reset();
 }
 
 }  // namespace metrics