Isolate initiation counts for downloads to their own histograms and improve

content/browser/download/download_stats.cc

 // Copyright (c) 2011 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_stats.h"
 
 #include "base/metrics/histogram.h"
 #include "base/string_util.h"
 #include "content/browser/download/download_resource_handler.h"
 #include "content/browser/download/interrupt_reasons.h"
 
 namespace download_stats {
 
 // All possible error codes from the network module. Note that the error codes
 // are all positive (since histograms expect positive sample values).
 const int kAllInterruptReasonCodes[] = {
 #define INTERRUPT_REASON(label, value) (value),
 #include "content/browser/download/interrupt_reason_values.h"
 #undef INTERRUPT_REASON
 };
 
 void RecordDownloadCount(DownloadCountTypes type) {
   UMA_HISTOGRAM_ENUMERATION(
       "Download.Counts", type, DOWNLOAD_COUNT_TYPES_LAST_ENTRY);
 }
 
+void RecordDownloadSource(DownloadSource source) {
+  UMA_HISTOGRAM_ENUMERATION(
+      "Download.Sources", source, DOWNLOAD_SOURCE_LAST_ENTRY);
+}
+
 void RecordDownloadCompleted(const base::TimeTicks& start, int64 download_len) {
   RecordDownloadCount(COMPLETED_COUNT);
   UMA_HISTOGRAM_LONG_TIMES("Download.Time", (base::TimeTicks::Now() - start));
   int64 max = 1024 * 1024 * 1024;  // One Terabyte.
   download_len /= 1024;  // In Kilobytes
   UMA_HISTOGRAM_CUSTOM_COUNTS("Download.DownloadSize",
                               download_len,
                               1,
                               max,
                               256);
@@ skipping 255 matching lines @@
 
 void RecordOpensOutstanding(int size) {
   UMA_HISTOGRAM_CUSTOM_COUNTS("Download.OpensOutstanding",
                               size,
                               0/*min*/,
                               (1 << 10)/*max*/,
                               64/*num_buckets*/);
 }
 
 }  // namespace download_stats