Replace GetAllErrorCodesForUma calls with UMA_HISTOGRAM_SPARSE_SLOWLY.

content/browser/download/download_resource_handler.cc

 // Copyright (c) 2012 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 "content/browser/download/download_resource_handler.h"
 
 #include <string>
 
 #include "base/bind.h"
 #include "base/logging.h"
 #include "base/message_loop/message_loop_proxy.h"
-#include "base/metrics/histogram.h"
+#include "base/metrics/histogram_macros.h"
+#include "base/metrics/sparse_histogram.h"
 #include "base/strings/stringprintf.h"
 #include "content/browser/byte_stream.h"
 #include "content/browser/download/download_create_info.h"
 #include "content/browser/download/download_interrupt_reasons_impl.h"
 #include "content/browser/download/download_manager_impl.h"
 #include "content/browser/download/download_request_handle.h"
 #include "content/browser/download/download_stats.h"
 #include "content/browser/loader/resource_dispatcher_host_impl.h"
 #include "content/browser/loader/resource_request_info_impl.h"
 #include "content/public/browser/browser_thread.h"
@@ skipping 423 matching lines @@
   CallStartedCB(NULL, reason);
 
   // Send the info down the stream.  Conditional is in case we get
   // OnResponseCompleted without OnResponseStarted.
   if (stream_writer_)
     stream_writer_->Close(reason);
 
   // If the error mapped to something unknown, record it so that
   // we can drill down.
   if (reason == DOWNLOAD_INTERRUPT_REASON_NETWORK_FAILED) {
-    UMA_HISTOGRAM_CUSTOM_ENUMERATION("Download.MapErrorNetworkFailed",
-                                     std::abs(status.error()),
-                                     net::GetAllErrorCodesForUma());
+    UMA_HISTOGRAM_SPARSE_SLOWLY("Download.MapErrorNetworkFailed",
+                                std::abs(status.error()));
   }
 
   stream_writer_.reset();  // We no longer need the stream.
   read_buffer_ = NULL;
 }
 
 void DownloadResourceHandler::OnDataDownloaded(int bytes_downloaded) {
   NOTREACHED();
 }
 
@@ skipping 69 matching lines @@
     BrowserThread::PostTask(
         BrowserThread::UI, FROM_HERE,
         base::Bind(&DeleteOnUIThread, base::Passed(&tab_info_)));
   }
 
   UMA_HISTOGRAM_TIMES("SB2.DownloadDuration",
                       base::TimeTicks::Now() - download_start_time_);
 }
 
 }  // namespace content