Add UMA histograms for home page, start page, and DSE hosts.

chrome/browser/prefs/pref_metrics_service.cc

Index: chrome/browser/prefs/pref_metrics_service.cc
diff --git a/chrome/browser/prefs/pref_metrics_service.cc b/chrome/browser/prefs/pref_metrics_service.cc
index ed1d5380e5849a2e828a2951ac73b4e25d494df8..f6b677276a7e75479f638a3df3f33f6ee7882257 100644
--- a/chrome/browser/prefs/pref_metrics_service.cc
+++ b/chrome/browser/prefs/pref_metrics_service.cc
@@ -4,12 +4,92 @@
 
 #include "chrome/browser/prefs/pref_metrics_service.h"
 
+#include <map>
+
 #include "base/metrics/histogram.h"
 #include "base/prefs/pref_service.h"
+#include "chrome/browser/prefs/session_startup_pref.h"
 #include "chrome/browser/profiles/incognito_helpers.h"
 #include "chrome/browser/profiles/profile.h"
+#include "chrome/browser/search_engines/template_url_prepopulate_data.h"
+#include "chrome/browser/search_engines/template_url_service.h"
+#include "chrome/browser/search_engines/template_url_service_factory.h"
 #include "chrome/common/pref_names.h"
 #include "components/browser_context_keyed_service/browser_context_dependency_manager.h"
+#include "net/base/registry_controlled_domains/registry_controlled_domain.h"
+
+using TemplateURLPrepopulateData::kMaxPrepopulatedEngineID;
+
+namespace {
+
+typedef std::map<std::string, int> DomainIdMap;

[Mark P, 2013/07/30 15:32:56]

nit: please comment me; what does the int mean / where do the ids come from?

[bbudge, 2013/07/30 18:47:08]

Done.

+
+// Returns the domain of the host name for easier matching.
+std::string GetDomain(const std::string& host) {
+  return std::string(

[Mark P, 2013/07/30 15:32:56]

Why do you need this std::string()?

[bbudge, 2013/07/30 18:47:08]

Right, I don't need it. Done.

+      net::registry_controlled_domains::GetDomainAndRegistry(
+          host,
+          net::registry_controlled_domains::EXCLUDE_PRIVATE_REGISTRIES));
+}
+
+void AddDomain(const std::string& domain,
+               int domain_id,
+               DomainIdMap* domain_id_map) {
+  domain_id_map->insert(std::make_pair(domain, domain_id));
+}
+
+// Builds a map that associates domain name strings with histogram enum values,
+// for prepopulated DSEs and select non-prepopulated ones.
+void BuildDomainIdMap(Profile* profile, DomainIdMap* domain_id_map) {
+  // Add prepopulated search engine hosts to the map.
+  ScopedVector<TemplateURL> prepopulated_urls;
+  size_t default_search_index;

[Mark P, 2013/07/30 15:32:56]

nit: // unused

[bbudge, 2013/07/30 18:47:08]

Done.

+  TemplateURLPrepopulateData::GetPrepopulatedEngines(profile,
+      &prepopulated_urls.get(), &default_search_index);
+  for (size_t i = 0; i < prepopulated_urls.size(); ++i) {
+    std::string domain(GetDomain(prepopulated_urls[i]->url_ref().GetHost()));
+    AddDomain(domain,
+              prepopulated_urls[i]->prepopulate_id(),
+              domain_id_map);
+  }
+  // Add some common search engine domains that are not prepopulated. Assign
+  // these domains id numbers 102-114 which extend the prepopulated engines
+  // histogram enum. If these new domains are removed, restore this range to
+  // the list of available ids in the prepopulated_engines.json file.

[Mark P, 2013/07/30 15:32:56]

This last sentence is bad advice.  We shouldn't restore enums to the range--that
would imply reuse of the particular enums, which can be misleading about what
domain name a particular bucket in an upload means.

[bbudge, 2013/07/30 18:47:08]

Yes, I suppose ids are forever. Removed comment.

+  AddDomain("searchnu.com", 102, domain_id_map);
+  AddDomain("babylon.com", 103, domain_id_map);
+  AddDomain("delta-search.com", 104, domain_id_map);
+  AddDomain("iminent.com", 105, domain_id_map);
+  AddDomain("hao123.com", 106, domain_id_map);
+  AddDomain("sweetim.com", 107, domain_id_map);
+  AddDomain("snap.do", 108, domain_id_map);
+  AddDomain("snapdo.com", 109, domain_id_map);
+  AddDomain("softonic.com", 110, domain_id_map);
+  AddDomain("searchfunmoods.com", 111, domain_id_map);
+  AddDomain("incredibar.com", 112, domain_id_map);
+  AddDomain("sweetpacks.com", 113, domain_id_map);
+  AddDomain("imesh.net", 114, domain_id_map);
+  // IMPORTANT: If you add more domains here, be sure to update the
+  // kMaxPrepopulatedEngineID and available ids in prepopulated_engines.json.
+
+  // The following hosts may not be prepopulated, depending on the country
+  // settings. Add them here, using their existing ids. See histograms.xml.
+  AddDomain("conduit.com", 36, domain_id_map);
+  AddDomain("avg.com", 50, domain_id_map);
+  AddDomain("mail.ru", 83, domain_id_map);
+}
+
+// Maps a host name to a histogram enum value. The enum value '0' represents
+// 'Unknown', i.e. an unrecognized host.
+int MapHostToId(const DomainIdMap& domain_id_map, const std::string& host) {
+  std::string domain(GetDomain(host));
+  DomainIdMap::const_iterator it = domain_id_map.find(domain);

[Mark P, 2013/07/30 15:32:56]

nit: just call GetDomain directly.

[bbudge, 2013/07/30 18:47:08]

Done.

+  if (it != domain_id_map.end())
+    return it->second;
+  return 0;
+}
+
+}  // namespace
 
 PrefMetricsService::PrefMetricsService(Profile* profile)
     : profile_(profile) {
@@ -20,10 +100,54 @@ PrefMetricsService::~PrefMetricsService() {
 }
 
 void PrefMetricsService::RecordLaunchPrefs() {
-  UMA_HISTOGRAM_BOOLEAN("Settings.ShowHomeButton",
-      profile_->GetPrefs()->GetBoolean(prefs::kShowHomeButton));
-  UMA_HISTOGRAM_BOOLEAN("Settings.HomePageIsNewTabPage",
-      profile_->GetPrefs()->GetBoolean(prefs::kHomePageIsNewTabPage));
+  PrefService* prefs = profile_->GetPrefs();
+  const bool show_home_button = prefs->GetBoolean(prefs::kShowHomeButton);
+  const bool home_page_is_ntp = prefs->GetBoolean(prefs::kHomePageIsNewTabPage);
+
+  UMA_HISTOGRAM_BOOLEAN("Settings.ShowHomeButton", show_home_button);
+  UMA_HISTOGRAM_BOOLEAN("Settings.HomePageIsNewTabPage", home_page_is_ntp);
+
+  DomainIdMap domain_id_map;
+  BuildDomainIdMap(profile_, &domain_id_map);
+
+  // Record the default search engine id.
+  TemplateURLService* template_url_service =
+      TemplateURLServiceFactory::GetForProfile(profile_);
+  if (template_url_service) {
+    TemplateURL* template_url =
+        template_url_service->GetDefaultSearchProvider();
+    if (template_url) {
+      int domain_id =

[Mark P, 2013/07/30 15:32:56]

const
or
just put it on the UMA_HISTOGRAM line directly

[bbudge, 2013/07/30 18:47:08]

Made these const. Done.

+          MapHostToId(domain_id_map, template_url->url_ref().GetHost());
+      UMA_HISTOGRAM_ENUMERATION("Settings.DefaultSearchProvider",
+                                domain_id, kMaxPrepopulatedEngineID);
+    }
+  }
+  // If the home page isn't the NTP, record the home page domain id.
+  if (!home_page_is_ntp) {
+    GURL homepage_url(prefs->GetString(prefs::kHomePage));
+    if (homepage_url.is_valid()) {
+      int domain_id = MapHostToId(domain_id_map, homepage_url.host());
+      UMA_HISTOGRAM_ENUMERATION("Settings.HomePageDomain",
+                                domain_id, kMaxPrepopulatedEngineID);
+    }
+  }
+  // If startup pages are set, record all startup page domain ids.
+  int restore_on_startup = prefs->GetInteger(prefs::kRestoreOnStartup);
+  if (restore_on_startup == SessionStartupPref::kPrefValueURLs) {
+    const ListValue* url_list = prefs->GetList(prefs::kURLsToRestoreOnStartup);
+    for (size_t i = 0; i < url_list->GetSize(); i++) {
+      std::string url_text;
+      if (url_list->GetString(i, &url_text)) {
+        GURL start_url(url_text);
+        if (start_url.is_valid()) {
+          int domain_id = MapHostToId(domain_id_map, start_url.host());
+          UMA_HISTOGRAM_ENUMERATION("Settings.StartPageDomains",
+                                    domain_id, kMaxPrepopulatedEngineID);
+        }
+      }
+    }
+  }
 }
 
 // static
@@ -42,6 +166,7 @@ PrefMetricsService::Factory::Factory()
     : BrowserContextKeyedServiceFactory(
         "PrefMetricsService",
         BrowserContextDependencyManager::GetInstance()) {
+  DependsOn(TemplateURLServiceFactory::GetInstance());
 }
 
 PrefMetricsService::Factory::~Factory() {