Add histograms to track synced pref changes.

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 97dc45d5257dd4c4c3c45437cda7a9413f4d7e04..37ff9256027f8da79ba3607c7f5d52469804b42a 100644
--- a/chrome/browser/prefs/pref_metrics_service.cc
+++ b/chrome/browser/prefs/pref_metrics_service.cc
@@ -8,12 +8,15 @@
 
 #include "base/metrics/histogram.h"
 #include "base/prefs/pref_service.h"
+#include "chrome/browser/prefs/pref_service_syncable.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/browser/sync/profile_sync_service.h"
+#include "chrome/browser/sync/profile_sync_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"
@@ -22,77 +25,24 @@ using TemplateURLPrepopulateData::kMaxPrepopulatedEngineID;
 
 namespace {
 
-// Use a map to convert domains to their histogram identifiers. Ids are defined
-// in tools/metrics/histograms/histograms.xml and (usually) also in
-// chrome/browser/search_engines/prepopulated_engines.json.
-typedef std::map<std::string, int> DomainIdMap;
-
 // Converts a host name into a domain name for easier matching.
-std::string GetDomain(const std::string& host) {
+std::string GetDomainFromHost(const std::string& host) {
   return 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;  // unused
-  TemplateURLPrepopulateData::GetPrepopulatedEngines(profile,
-      &prepopulated_urls.get(), &default_search_index);
-  for (size_t i = 0; i < prepopulated_urls.size(); ++i) {
-    AddDomain(GetDomain(prepopulated_urls[i]->url_ref().GetHost()),
-              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.
-  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) {
-  DomainIdMap::const_iterator it = domain_id_map.find(GetDomain(host));
-  if (it != domain_id_map.end())
-    return it->second;
-  return 0;
-}
-
 }  // namespace
 
 PrefMetricsService::PrefMetricsService(Profile* profile)
     : profile_(profile) {
+  BuildDomainIdMap();
   RecordLaunchPrefs();
+
+  PrefServiceSyncable* prefs = PrefServiceSyncable::FromProfile(profile_);
+  synced_pref_change_registrar_.reset(new SyncedPrefChangeRegistrar(prefs));
+
+  RegisterSyncedPrefObservers();
 }
 
 PrefMetricsService::~PrefMetricsService() {
@@ -117,9 +67,6 @@ void PrefMetricsService::RecordLaunchPrefs() {
         "Settings.StartupPageLoadURLs", url_list_size, 1, 50, 20);
   }
 
-  DomainIdMap domain_id_map;
-  BuildDomainIdMap(profile_, &domain_id_map);
-
   // Record the default search engine id.
   TemplateURLService* template_url_service =
       TemplateURLServiceFactory::GetForProfile(profile_);
@@ -127,8 +74,7 @@ void PrefMetricsService::RecordLaunchPrefs() {
     TemplateURL* template_url =
         template_url_service->GetDefaultSearchProvider();
     if (template_url) {
-      const int domain_id =
-          MapHostToId(domain_id_map, template_url->url_ref().GetHost());
+      const int domain_id = MapHostToId(template_url->url_ref().GetHost());
       UMA_HISTOGRAM_ENUMERATION("Settings.DefaultSearchProvider",
                                 domain_id, kMaxPrepopulatedEngineID);
     }
@@ -137,7 +83,7 @@ void PrefMetricsService::RecordLaunchPrefs() {
   if (!home_page_is_ntp) {
     GURL homepage_url(prefs->GetString(prefs::kHomePage));
     if (homepage_url.is_valid()) {
-      const int domain_id = MapHostToId(domain_id_map, homepage_url.host());
+      const int domain_id = MapHostToId(homepage_url.host());
       UMA_HISTOGRAM_ENUMERATION("Settings.HomePageDomain",
                                 domain_id, kMaxPrepopulatedEngineID);
     }
@@ -150,7 +96,7 @@ void PrefMetricsService::RecordLaunchPrefs() {
       if (url_list->GetString(i, &url_text)) {
         GURL start_url(url_text);
         if (start_url.is_valid()) {
-          const int domain_id = MapHostToId(domain_id_map, start_url.host());
+          const int domain_id = MapHostToId(start_url.host());
           UMA_HISTOGRAM_ENUMERATION("Settings.StartupPageDomains",
                                     domain_id, kMaxPrepopulatedEngineID);
         }
@@ -159,6 +105,148 @@ void PrefMetricsService::RecordLaunchPrefs() {
   }
 }
 
+void PrefMetricsService::RegisterSyncedPrefObservers() {
+  ValueHistogramCallback booleanHandler = base::Bind(
+      &PrefMetricsService::LogBooleanPrefChange, base::Unretained(this));
+  ValueHistogramCallback urlHandler = base::Bind(
+      &PrefMetricsService::LogUrlPrefChange, base::Unretained(this));
+
+  AddPrefObserver(prefs::kShowHomeButton, "ShowHomeButton", booleanHandler);
+  AddPrefObserver(prefs::kHomePageIsNewTabPage, "HomePageIsNewTabPage",
+                  booleanHandler);
+  AddPrefObserver(prefs::kHomePage, "HomePageDomain", urlHandler);
+
+  const int startupPrefValueMax = SessionStartupPref::kPrefValueMax;
+  AddPrefObserver(prefs::kRestoreOnStartup, "StartupPageLoadSettings",
+                  base::Bind(&PrefMetricsService::LogIntegerPrefChange,
+                             base::Unretained(this),
+                             startupPrefValueMax));
+
+  AddPrefObserver(prefs::kURLsToRestoreOnStartup, "StartupPageDomains",
+                  base::Bind(&PrefMetricsService::LogListPrefChange,
+                             base::Unretained(this),
+                             urlHandler));
+}
+
+void PrefMetricsService::AddPrefObserver(
+    const std::string& path,
+    const std::string& histogram_base,
+    const ValueHistogramCallback& callback) {
+  synced_pref_change_registrar_->Add(path.c_str(),
+      base::Bind(&PrefMetricsService::OnPrefChanged,
+                 base::Unretained(this),
+                 histogram_base, callback));
+}
+
+void PrefMetricsService::BuildDomainIdMap() {
+  // Add prepopulated search engine hosts to the map.
+  ScopedVector<TemplateURL> prepopulated_urls;
+  size_t default_search_index;  // unused
+  TemplateURLPrepopulateData::GetPrepopulatedEngines(profile_,
+      &prepopulated_urls.get(), &default_search_index);
+  for (size_t i = 0; i < prepopulated_urls.size(); ++i) {
+    AddToDomainIdMap(
+        GetDomainFromHost(prepopulated_urls[i]->url_ref().GetHost()),
+        prepopulated_urls[i]->prepopulate_id());
+  }
+  // Add some common search engine domains that are not prepopulated. Assign
+  // these domains id numbers 102-114 which extend the prepopulated engines
+  // histogram enum.
+  AddToDomainIdMap("searchnu.com", 102);
+  AddToDomainIdMap("babylon.com", 103);
+  AddToDomainIdMap("delta-search.com", 104);
+  AddToDomainIdMap("iminent.com", 105);
+  AddToDomainIdMap("hao123.com", 106);
+  AddToDomainIdMap("sweetim.com", 107);
+  AddToDomainIdMap("snap.do", 108);
+  AddToDomainIdMap("snapdo.com", 109);
+  AddToDomainIdMap("softonic.com", 110);
+  AddToDomainIdMap("searchfunmoods.com", 111);
+  AddToDomainIdMap("incredibar.com", 112);
+  AddToDomainIdMap("sweetpacks.com", 113);
+  AddToDomainIdMap("imesh.net", 114);
+  // 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.
+  AddToDomainIdMap("conduit.com", 36);
+  AddToDomainIdMap("avg.com", 50);
+  AddToDomainIdMap("mail.ru", 83);
+}
+
+void PrefMetricsService::AddToDomainIdMap(const std::string& domain,
+    int domain_id) {
+  domain_id_map_.insert(std::make_pair(domain, domain_id));
+}
+
+int PrefMetricsService::MapHostToId(const std::string& host) const {
+  DomainIdMap::const_iterator it = domain_id_map_.find(
+      GetDomainFromHost(host));
+  if (it != domain_id_map_.end())
+    return it->second;
+  return 0;
+}
+
+void PrefMetricsService::OnPrefChanged(const std::string& histogram_base,
+                                       const ValueHistogramCallback& callback,
+                                       const std::string& path,
+                                       bool from_sync) {
+  PrefServiceSyncable* prefs = PrefServiceSyncable::FromProfile(profile_);
+  const PrefService::Preference* pref = prefs->FindPreference(path.c_str());
+  DCHECK(pref);
+  std::string source_name(
+      from_sync ? ".PulledFromSync" : "PushedToSync");

[bbudge, 2013/08/01 17:48:08]

Why is one prefixed with '.' and not the other?

[Ken Rockot(use gerrit already), 2013/08/01 17:55:15]

Good catch. Fixed.

+  std::string histogram_name("Settings." + histogram_base + source_name);
+  callback.Run(histogram_name, pref->GetValue());
+};
+
+void PrefMetricsService::LogBooleanPrefChange(const std::string& histogram_name,
+                                              const Value* value) {
+  bool boolean_value = false;
+  if (!value->GetAsBoolean(&boolean_value))
+    return;
+  UMA_HISTOGRAM_BOOLEAN(histogram_name.c_str(), boolean_value);
+}
+
+void PrefMetricsService::LogIntegerPrefChange(int boundary_value,
+                                              const std::string& histogram_name,
+                                              const Value* value) {
+  int integer_value = 0;
+  if (!value->GetAsInteger(&integer_value))
+    return;
+  UMA_HISTOGRAM_ENUMERATION(histogram_name.c_str(), integer_value,
+                            boundary_value);
+}
+
+void PrefMetricsService::LogUrlPrefChange(const std::string& histogram_name,
+                                          const Value* value) {
+  std::string string_value;
+  if (!value->GetAsString(&string_value))
+    return;
+  GURL url(string_value);
+  if (url.is_valid()) {
+    int domain_id = MapHostToId(url.host());
+    UMA_HISTOGRAM_ENUMERATION(histogram_name.c_str(), domain_id,
+                              kMaxPrepopulatedEngineID);
+  }
+}
+
+void PrefMetricsService::LogListPrefChange(
+    const ValueHistogramCallback& item_callback,
+    const std::string& histogram_name,
+    const Value* value) {
+  const ListValue* items = NULL;
+  if (!value->GetAsList(&items))
+    return;
+  for (size_t i = 0; i < items->GetSize(); ++i) {
+    const Value *item_value = NULL;
+    if (items->Get(i, &item_value)) {
+      item_callback.Run(histogram_name, item_value);
+    }
+  }
+}
+
 // static
 PrefMetricsService::Factory* PrefMetricsService::Factory::GetInstance() {
   return Singleton<PrefMetricsService::Factory>::get();
@@ -176,6 +264,7 @@ PrefMetricsService::Factory::Factory()
         "PrefMetricsService",
         BrowserContextDependencyManager::GetInstance()) {
   DependsOn(TemplateURLServiceFactory::GetInstance());
+  DependsOn(ProfileSyncServiceFactory::GetInstance());
 }
 
 PrefMetricsService::Factory::~Factory() {