Added of new UMA signals in order to be able to discover early if the "save password" feature gets …

chrome/browser/password_manager/password_manager_metrics_util.cc

+// Copyright 2013 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 "chrome/browser/password_manager/password_manager_metrics_util.h"
+
+#include "base/basictypes.h"
+#include "base/metrics/histogram.h"
+#include "base/rand_util.h"
+#include "base/strings/string_number_conversions.h"
+#include "base/strings/string_util.h"
+#include "base/time/time.h"
+#include "url/gurl.h"
+
+namespace password_manager_metrics_util {
+
+namespace {
+
+// The number of domain groups.
+const size_t kNumGroups = 20u;

[vabr (Chromium), 2013/09/12 13:40:02]

Why not kNumGroups = 2 * kGroupsPerDomain?
That would spare you the comment at kGroupsPerDomain about being a half, and
also make sure that this relation always holds.

[jdomingos, 2013/09/12 16:33:52]

Done.

+
+size_t g_random_group_id = kGroupsPerDomain;
+
+}  // namespace
+
+// Contains a monitored domain name and all the group IDs which contain
+// domain name.
+struct DomainGroupsPair {
+  const char* const domain_name;
+  const int group_ids[kGroupsPerDomain];
+};
+
+unsigned int MonitoredDomainGroupId(const std::string& url_host) {
+  // This array contains each monitored website together with all ids of
+  // groups which contain the website. Each website appears in
+  // |kGroupsPerDomain| groups, and each group includes an equal number of
+  // websites, so that no two websites have the same set of groups that they
+  // belong to. All ids are in the range [1, |kNumGroups|].
+  // For more information about the algorithm used see http://goo.gl/vUuFd5.
+  static const DomainGroupsPair kDomainMapping[] = {
+      {"google.com", {1, 2, 3, 4, 5, 6, 7, 8, 9, 10}},
+      {"yahoo.com", {1, 2, 3, 4, 5, 11, 12, 13, 14, 15}},
+      {"baidu.com", {1, 2, 3, 4, 6, 7, 11, 12, 16, 17}},
+      {"wikipedia.org", {1, 2, 3, 4, 5, 6, 11, 12, 16, 18}},
+      {"linkedin.com", {1, 6, 8, 11, 13, 14, 15, 16, 17, 19}},
+      {"twitter.com", {5, 6, 7, 8, 9, 11, 13, 17, 19, 20}},
+      {"live.com", {7, 8, 9, 10, 13, 14, 16, 17, 18, 20}},
+      {"amazon.com", {2, 5, 9, 10, 12, 14, 15, 18, 19, 20}},
+      {"ebay.com", {3, 7, 9, 10, 14, 15, 17, 18, 19, 20}},
+      {"tumblr.com", {4, 8, 10, 12, 13, 15, 16, 18, 19, 20}},
+  };
+  const size_t kDomainMappingLength = arraysize(kDomainMapping);
+
+  GenerateRandomId();
+
+  GURL url(url_host);
+  for (size_t i = 0; i < kDomainMappingLength; ++i) {
+    if (url.DomainIs(kDomainMapping[i].domain_name))
+      return kDomainMapping[i].group_ids[g_random_group_id];
+  }
+  return 0;
+}
+
+void LogUMAHistogramEnumeration(const std::string& name,
+                                int sample,
+                                int boundary_value) {
+  DCHECK_LT(sample, boundary_value);
+
+  // Note: This leaks memory, which is expected behavior.
+  base::HistogramBase* histogram =
+      base::LinearHistogram::FactoryGet(
+          name,
+          1,
+          boundary_value,
+          boundary_value + 1,
+          base::HistogramBase::kUmaTargetedHistogramFlag);
+  histogram->Add(sample);
+}
+
+void LogUMAHistogramCounts(const std::string& name, int sample) {
+  // Note: This leaks memory, which is expected behavior.
+  base::HistogramBase* histogram =
+      base::Histogram::FactoryGet(
+          name,
+          1,
+          1000000,
+          kNumGroups,
+          base::HistogramBase::kUmaTargetedHistogramFlag);
+  histogram->Add(sample);
+}
+
+void LogUMAHistogramBoolean(const std::string& name, bool sample) {
+  // Note: This leaks memory, which is expected behavior.
+  base::HistogramBase* histogram =
+      base::BooleanHistogram::FactoryGet(
+          name,
+          base::Histogram::kNoFlags);
+          histogram->AddBoolean(sample);
+}
+
+// Generate an id in range [0, |kGroupsPerDomain|).
+// If the |random_group_id| is equal to its initial value (|kGroupsPerDomain|),
+// the value of |random_id| is not changed.
+void GenerateRandomId() {
+  // For each session, the user uses only one group for each website.
+  if (g_random_group_id == kGroupsPerDomain)
+    g_random_group_id = base::RandGenerator(kGroupsPerDomain);
+}
+
+void SetRandomIdForTesting(unsigned int value) {
+  g_random_group_id = value;
+}
+
+std::string GroupIdToString(unsigned int group_id) {
+  if (group_id > 0 && group_id <= kNumGroups)
+    return "group_" + base::IntToString(group_id);
+  return "";
+}
+
+}  // namespace password_manager_metrics_util