Add new UMA stats to get a handle on Downloads UI Usage

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"
 
 namespace download_stats {
@@ skipping 155 matching lines @@
       download_content = DOWNLOAD_CONTENT_VIDEO;
     }
   }
 
   // Record the value.
   UMA_HISTOGRAM_ENUMERATION("Download.ContentType",
                             download_content,
                             DOWNLOAD_CONTENT_MAX);
 }
 
+void RecordOpen(const base::Time& end, bool first) {
+  if (!end.is_null()) {
+    UMA_HISTOGRAM_LONG_TIMES("Download.OpenTime", (base::Time::Now() - end));
+    if (first) {
+      UMA_HISTOGRAM_LONG_TIMES("Download.FirstOpenTime",
+                              (base::Time::Now() - end));
+    }
+  }
+}
+
+void RecordHistorySize(int size) {
+  UMA_HISTOGRAM_CUSTOM_COUNTS("Download.HistorySize",
+                              size,
+                              0/*min*/,
+                              kint32max/*max*/,
+                              (1 << 10)/*num_buckets*/);

[Randy Smith (Not in Mondays), 2011/09/30 15:57:21]

Why such large numbers for max and num buckets (especially buckets, since that's
memory space)?  I'd pick a number over which the conclusion would be "Ok, they
just don't clear their downloads", and not worry about getting data about the
nuances above that.  I'm also not sure what question we're trying to answer with
1024 buckets; that seems like overkill.  Enlighten me?

[benjhayden, 2011/10/03 20:54:39]

Done.

+}
+
+void RecordHistorySize2(int size) {
+  UMA_HISTOGRAM_CUSTOM_COUNTS("Download.HistorySize2",
+                              size,
+                              0/*min*/,
+                              kint32max/*max*/,
+                              (1 << 10)/*num_buckets*/);

[Randy Smith (Not in Mondays), 2011/09/30 15:57:21]

See above.

[benjhayden, 2011/10/03 20:54:39]

Done.

+}
+
+void RecordShelfSize(int size) {
+  UMA_HISTOGRAM_ENUMERATION("Download.ShelfSize",
+                            size,
+                            128);
+}
+
+void RecordShelfPendingSize(int size) {
+  UMA_HISTOGRAM_ENUMERATION("Download.ShelfPendingSize",
+                            size,
+                            128);
+}
+
+void RecordClearAllSize(int size) {
+  UMA_HISTOGRAM_CUSTOM_COUNTS("Download.ClearAllSize",
+                              size,
+                              0/*min*/,
+                              kint32max/*max*/,
+                              (1 << 10)/*num_buckets*/);

[Randy Smith (Not in Mondays), 2011/09/30 15:57:21]

See above.  I'd imagine we're really only interested in three buckets here: 1)
Clear every time, 2) Clear before too long, 3) Never (or almost never) clear.

[benjhayden, 2011/10/03 20:54:39]

I thought that we were also looking to objectively quantify "before too long",
so I set all the "big" ones to 1024 max, 32 buckets.

+}
+
+void RecordOpensOutstanding(int size) {
+  UMA_HISTOGRAM_CUSTOM_COUNTS("Download.OpensOutstanding",
+                              size,
+                              0/*min*/,
+                              kint32max/*max*/,
+                              (1 << 10)/*num_buckets*/);

[Randy Smith (Not in Mondays), 2011/09/30 15:57:21]

See comment immediately above (including the three buckets).  I don't mind more
buckets, but I don't want to gobble a lot of chrome memory without having a
specific question in mind I'm trying to answer.

[benjhayden, 2011/10/03 20:54:39]

Done.

+}
+
 }  // namespace download_stats