Adding UMA for sync service, to see how many MEMORY_PRESSURE_LEVEL_CRITICAL received.

BUG=488290

Review URL: https://codereview.chromium.org/1136763004

Cr-Commit-Position: refs/heads/master@{#330253}

8 files changed, 162 insertions, 0 deletions

diff --git a/chrome/browser/sync/profile_sync_service.cc b/chrome/browser/sync/profile_sync_service.cc
index 2ac3dee..5f0bffd 100644
--- a/chrome/browser/sync/profile_sync_service.cc
+++ b/chrome/browser/sync/profile_sync_service.cc
@@ -365,6 +365,8 @@ void ProfileSyncService::Initialize() {
   DCHECK(!running_rollback);
 #endif
 
+  memory_pressure_listener_.reset(new base::MemoryPressureListener(base::Bind(
+      &ProfileSyncService::OnMemoryPressure, weak_factory_.GetWeakPtr())));
   startup_controller_->Reset(GetRegisteredDataTypes());
   startup_controller_->TryStart();
 }
@@ -702,6 +704,8 @@ void ProfileSyncService::StartUpSlowBackendComponents(
   InitializeBackend(ShouldDeleteSyncFolder());
 
   UpdateFirstSyncTimePref();
+
+  ReportPreviousSessionMemoryWarningCount();
 }
 
 void ProfileSyncService::OnGetTokenSuccess(
@@ -912,6 +916,9 @@ void ProfileSyncService::ShutdownImpl(syncer::ShutdownReason reason) {
     UpdateAuthErrorState(GoogleServiceAuthError::AuthErrorNone());
 
   NotifyObservers();
+
+  // Mark this as a clean shutdown(without crash).
+  sync_prefs_.SetCleanShutdown(true);
 }
 
 void ProfileSyncService::DisableForUser() {
@@ -2720,3 +2727,31 @@ void ProfileSyncService::RemoveClientFromServer() const {
         access_token_, cache_guid, birthday);
   }
 }
+
+void ProfileSyncService::OnMemoryPressure(
+    base::MemoryPressureListener::MemoryPressureLevel memory_pressure_level) {
+  if (memory_pressure_level ==
+      base::MemoryPressureListener::MEMORY_PRESSURE_LEVEL_CRITICAL) {
+    sync_prefs_.SetMemoryPressureWarningCount(
+        sync_prefs_.GetMemoryPressureWarningCount() + 1);
+  }
+}
+
+void ProfileSyncService::ReportPreviousSessionMemoryWarningCount() {
+  int warning_received = sync_prefs_.GetMemoryPressureWarningCount();
+
+  if (-1 != warning_received) {
+    // -1 means it is new client.
+    if (!sync_prefs_.DidSyncShutdownCleanly()) {
+      UMA_HISTOGRAM_COUNTS("Sync.MemoryPressureWarningBeforeUncleanShutdown",
+                           warning_received);
+    } else {
+      UMA_HISTOGRAM_COUNTS("Sync.MemoryPressureWarningBeforeCleanShutdown",
+                           warning_received);
+    }
+  }
+  sync_prefs_.SetMemoryPressureWarningCount(0);
+  // Will set to true during a clean shutdown, so crash or something else will
+  // remain this as false.
+  sync_prefs_.SetCleanShutdown(false);
+}
diff --git a/chrome/browser/sync/profile_sync_service.h b/chrome/browser/sync/profile_sync_service.h
index 1ad2cb7..ff2e2b0 100644
--- a/chrome/browser/sync/profile_sync_service.h
+++ b/chrome/browser/sync/profile_sync_service.h
@@ -14,6 +14,7 @@
 #include "base/files/file_path.h"
 #include "base/gtest_prod_util.h"
 #include "base/location.h"
+#include "base/memory/memory_pressure_listener.h"
 #include "base/memory/scoped_ptr.h"
 #include "base/memory/scoped_vector.h"
 #include "base/memory/weak_ptr.h"
@@ -891,6 +892,13 @@ class ProfileSyncService : public sync_driver::SyncService,
   // Tell the sync server that this client has disabled sync.
   void RemoveClientFromServer() const;
 
+  // Called when the system is under memory pressure.
+  void OnMemoryPressure(
+      base::MemoryPressureListener::MemoryPressureLevel memory_pressure_level);
+
+  // Check if previous shutdown is shutdown cleanly.
+  void ReportPreviousSessionMemoryWarningCount();
+
   // Factory used to create various dependent objects.
   scoped_ptr<ProfileSyncComponentsFactory> factory_;
 
@@ -1070,6 +1078,9 @@ class ProfileSyncService : public sync_driver::SyncService,
 
   scoped_ptr<browser_sync::SyncStoppedReporter> sync_stopped_reporter_;
 
+  // Listens for the system being under memory pressure.
+  scoped_ptr<base::MemoryPressureListener> memory_pressure_listener_;
+
   base::WeakPtrFactory<ProfileSyncService> weak_factory_;
 
   // We don't use |weak_factory_| for the StartupController because the weak
diff --git a/chrome/browser/sync/profile_sync_service_unittest.cc b/chrome/browser/sync/profile_sync_service_unittest.cc
index cba1633..f4cb23a 100644
--- a/chrome/browser/sync/profile_sync_service_unittest.cc
+++ b/chrome/browser/sync/profile_sync_service_unittest.cc
@@ -659,5 +659,50 @@ TEST_F(ProfileSyncServiceTest, NoDisableSyncFlag) {
   EXPECT_TRUE(ProfileSyncService::IsSyncEnabled());
 }
 
+// Test Sync will stop after receive memory pressure
+TEST_F(ProfileSyncServiceTest, MemoryPressureRecording) {
+  CreateService(browser_sync::AUTO_START);
+  IssueTestTokens();
+  ExpectDataTypeManagerCreation(1);
+  ExpectSyncBackendHostCreation(1);
+  InitializeForNthSync();
+
+  EXPECT_TRUE(service()->SyncActive());
+  EXPECT_FALSE(profile()->GetPrefs()->GetBoolean(
+      sync_driver::prefs::kSyncSuppressStart));
+
+  testing::Mock::VerifyAndClearExpectations(components_factory());
+
+  sync_driver::SyncPrefs sync_prefs(service()->profile()->GetPrefs());
+
+  EXPECT_EQ(profile()->GetPrefs()->GetInteger(
+                sync_driver::prefs::kSyncMemoryPressureWarningCount),
+            0);
+  EXPECT_FALSE(sync_prefs.DidSyncShutdownCleanly());
+
+  // Simulate memory pressure notification.
+  base::MemoryPressureListener::NotifyMemoryPressure(
+      base::MemoryPressureListener::MEMORY_PRESSURE_LEVEL_CRITICAL);
+  base::RunLoop().RunUntilIdle();
+
+  // Verify memory pressure recorded.
+  EXPECT_EQ(profile()->GetPrefs()->GetInteger(
+                sync_driver::prefs::kSyncMemoryPressureWarningCount),
+            1);
+  EXPECT_FALSE(sync_prefs.DidSyncShutdownCleanly());
+
+  // Simulate memory pressure notification.
+  base::MemoryPressureListener::NotifyMemoryPressure(
+      base::MemoryPressureListener::MEMORY_PRESSURE_LEVEL_CRITICAL);
+  base::RunLoop().RunUntilIdle();
+  ShutdownAndDeleteService();
+
+  // Verify memory pressure and shutdown recorded.
+  EXPECT_EQ(profile()->GetPrefs()->GetInteger(
+                sync_driver::prefs::kSyncMemoryPressureWarningCount),
+            2);
+  EXPECT_TRUE(sync_prefs.DidSyncShutdownCleanly());
+}
+
 }  // namespace
 }  // namespace browser_sync
diff --git a/components/sync_driver/pref_names.cc b/components/sync_driver/pref_names.cc
index 1a5727a..8caf875 100644
--- a/components/sync_driver/pref_names.cc
+++ b/components/sync_driver/pref_names.cc
@@ -104,6 +104,12 @@ const char kSyncFirstSyncTime[] = "sync.first_sync_time";
 // that we only want to use once.
 const char kSyncPassphrasePrompted[] = "sync.passphrase_prompted";
 
+// Stores how many times received MEMORY_PRESSURE_LEVEL_CRITICAL.
+const char kSyncMemoryPressureWarningCount[] = "sync.memory_warning_count";
+
+// Stores if sync shutdown cleanly.
+const char kSyncShutdownCleanly[] = "sync.shutdown_cleanly";
+
 }  // namespace prefs
 
 }  // namespace sync_driver
diff --git a/components/sync_driver/pref_names.h b/components/sync_driver/pref_names.h
index 3cbce22..2491390 100644
--- a/components/sync_driver/pref_names.h
+++ b/components/sync_driver/pref_names.h
@@ -66,6 +66,9 @@ extern const char kSyncFirstSyncTime[];
 
 extern const char kSyncPassphrasePrompted[];
 
+extern const char kSyncMemoryPressureWarningCount[];
+extern const char kSyncShutdownCleanly[];
+
 }  // namespace prefs
 
 }  // namespace sync_driver
diff --git a/components/sync_driver/sync_prefs.cc b/components/sync_driver/sync_prefs.cc
index 82106ee..9f80075 100644
--- a/components/sync_driver/sync_prefs.cc
+++ b/components/sync_driver/sync_prefs.cc
@@ -83,6 +83,10 @@ void SyncPrefs::RegisterProfilePrefs(
   registry->RegisterIntegerPref(prefs::kSyncRemainingRollbackTries, 0);
 
   registry->RegisterBooleanPref(prefs::kSyncPassphrasePrompted, false);
+
+  registry->RegisterIntegerPref(prefs::kSyncMemoryPressureWarningCount, -1);
+
+  registry->RegisterBooleanPref(prefs::kSyncShutdownCleanly, false);
 }
 
 void SyncPrefs::AddSyncPrefObserver(SyncPrefObserver* sync_pref_observer) {
@@ -455,4 +459,22 @@ void SyncPrefs::SetPassphrasePrompted(bool value) {
   pref_service_->SetBoolean(prefs::kSyncPassphrasePrompted, value);
 }
 
+int SyncPrefs::GetMemoryPressureWarningCount() const {
+  return pref_service_->GetInteger(prefs::kSyncMemoryPressureWarningCount);
+}
+
+void SyncPrefs::SetMemoryPressureWarningCount(int value) {
+  pref_service_->SetInteger(prefs::kSyncMemoryPressureWarningCount, value);
+}
+
+bool SyncPrefs::DidSyncShutdownCleanly() const {
+  return pref_service_->GetBoolean(prefs::kSyncShutdownCleanly);
+}
+
+void SyncPrefs::SetCleanShutdown(bool value) {
+  pref_service_->SetBoolean(prefs::kSyncShutdownCleanly, value);
+}
+
 }  // namespace sync_driver
+
+
diff --git a/components/sync_driver/sync_prefs.h b/components/sync_driver/sync_prefs.h
index 5a3abe5..10b3bcd 100644
--- a/components/sync_driver/sync_prefs.h
+++ b/components/sync_driver/sync_prefs.h
@@ -143,6 +143,16 @@ class SyncPrefs : NON_EXPORTED_BASE(public base::NonThreadSafe),
   // For testing.
   void SetManagedForTest(bool is_managed);
 
+  // Get/Set number of memory warnings received.
+  int GetMemoryPressureWarningCount() const;
+  void SetMemoryPressureWarningCount(int value);
+
+  // Check if the previous shutdown was clean.
+  bool DidSyncShutdownCleanly() const;
+
+  // Set whetherthe last shutdown was clean.
+  void SetCleanShutdown(bool value);
+
  private:
   void RegisterPrefGroups();
 
diff --git a/tools/metrics/histograms/histograms.xml b/tools/metrics/histograms/histograms.xml
index 5e4cd33..66efb9d 100644
--- a/tools/metrics/histograms/histograms.xml
+++ b/tools/metrics/histograms/histograms.xml
@@ -41796,6 +41796,36 @@ Therefore, the affected-histogram name has to have at least one dot in it.
   </summary>
 </histogram>
 
+<histogram name="Sync.MemoryPressureWarningBeforeCleanShutdown" units="count">
+  <owner>gangwu@chromium.org</owner>
+  <summary>
+    Counts the number of times a user's sync service received a
+    MEMORY_PRESSURE_LEVEL_CRITICAL warning before the sync service shut down
+    cleanly. The sync service emits this number the next time the user's sync
+    service is started, which will likely happen the next time the user's
+    profile is opened after a Chrome restart.  This count is emitted once per
+    user/profile. Things like browser crashes that implicitly bring down all
+    users' sync services will cause unclean shutdown tags to appear on all open
+    profiles, meaning that there will be multiple emissions to this histogram as
+    those profiles are re-opened.
+  </summary>
+</histogram>
+
+<histogram name="Sync.MemoryPressureWarningBeforeUncleanShutdown" units="count">
+  <owner>gangwu@chromium.org</owner>
+  <summary>
+    Counts the number of times a user's sync service received a
+    MEMORY_PRESSURE_LEVEL_CRITICAL warning before the sync service shut down
+    uncleanly. The sync service emits this number the next time the user's sync
+    service is started, which will likely happen the next time the user's
+    profile is opened after a Chrome restart.  This count is emitted once per
+    user/profile. Things like browser crashes that implicitly bring down all
+    users' sync services will cause unclean shutdown tags to appear on all open
+    profiles, meaning that there will be multiple emissions to this histogram as
+    those profiles are re-opened.
+  </summary>
+</histogram>
+
 <histogram name="Sync.NigoriMigrationState" enum="SyncNigoriMigrationState">
   <owner>zea@chromium.org</owner>
   <summary>Breakdown of sync's nigori node keystore migration state.</summary>