Showing the location of where nudges came from.

BUG=77006
TEST=

Committed: http://src.chromium.org/viewvc/chrome?view=rev&revision=80251

Review URL: http://codereview.chromium.org/6764019

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@80402 0039d316-1c4b-4281-b951-d872f2087c98

11 files changed, 128 insertions, 75 deletions

diff --git a/chrome/browser/sync/engine/syncapi.cc b/chrome/browser/sync/engine/syncapi.cc
index e1f35f0..89a9ded 100644
--- a/chrome/browser/sync/engine/syncapi.cc
+++ b/chrome/browser/sync/engine/syncapi.cc
@@ -1641,14 +1641,15 @@ bool SyncManager::RequestResume() {
   return false;
 }
 
-void SyncManager::RequestNudge() {
+void SyncManager::RequestNudge(const tracked_objects::Location& location) {
   if (data_->syncer_thread())
-    data_->syncer_thread()->NudgeSyncer(0, SyncerThread::kLocal);
+    data_->syncer_thread()->NudgeSyncer(0, SyncerThread::kLocal, location);
 }
 
 void SyncManager::RequestClearServerData() {
   if (data_->syncer_thread())
-    data_->syncer_thread()->NudgeSyncer(0, SyncerThread::kClearPrivateData);
+    data_->syncer_thread()->NudgeSyncer(0, SyncerThread::kClearPrivateData,
+        FROM_HERE);
 }
 
 void SyncManager::RequestConfig(const syncable::ModelTypeBitSet& types) {
@@ -1952,7 +1953,7 @@ void SyncManager::SyncInternal::SetPassphrase(
 
     // Nudge the syncer so that encrypted datatype updates that were waiting for
     // this passphrase get applied as soon as possible.
-    sync_manager_->RequestNudge();
+    sync_manager_->RequestNudge(FROM_HERE);
   } else {
     VLOG(1) << "No pending keys, adding provided passphrase.";
     WriteNode node(&trans);
@@ -2191,7 +2192,7 @@ void SyncManager::SyncInternal::OnIPAddressChangedImpl() {
   // TODO(akalin): CheckServerReachable() can block, which may cause
   // jank if we try to shut down sync.  Fix this.
   connection_manager()->CheckServerReachable();
-  sync_manager_->RequestNudge();
+  sync_manager_->RequestNudge(FROM_HERE);
 }
 
 // Listen to model changes, filter out ones initiated by the sync API, and
@@ -2337,7 +2338,8 @@ void SyncManager::SyncInternal::HandleCalculateChangesChangeEventFromSyncApi(
     syncer_thread()->NudgeSyncerWithDataTypes(
         nudge_delay,
         SyncerThread::kLocal,
-        model_types);
+        model_types,
+        FROM_HERE);
   }
 }
 
@@ -2664,7 +2666,7 @@ void SyncManager::SyncInternal::OnIncomingNotification(
       syncer_thread()->NudgeSyncerWithPayloads(
           kSyncerThreadDelayMsec,
           SyncerThread::kNotification,
-          type_payloads);
+          type_payloads, FROM_HERE);
     }
     allstatus_.IncrementNotificationsReceived();
     UpdateNotificationInfo(type_payloads);
diff --git a/chrome/browser/sync/engine/syncapi.h b/chrome/browser/sync/engine/syncapi.h
index 88e30fd..18da106 100644
--- a/chrome/browser/sync/engine/syncapi.h
+++ b/chrome/browser/sync/engine/syncapi.h
@@ -46,6 +46,7 @@
 #include "base/callback.h"
 #include "base/gtest_prod_util.h"
 #include "base/memory/scoped_ptr.h"
+#include "base/tracked.h"
 #include "build/build_config.h"
 #include "chrome/browser/sync/protocol/password_specifics.pb.h"
 #include "chrome/browser/sync/syncable/autofill_migration.h"
@@ -940,7 +941,7 @@ class SyncManager {
 
   // Request a nudge of the syncer, which will cause the syncer thread
   // to run at the next available opportunity.
-  void RequestNudge();
+  void RequestNudge(const tracked_objects::Location& nudge_location);
 
   // Request a clearing of all data on the server
   void RequestClearServerData();
diff --git a/chrome/browser/sync/engine/syncer_thread2.cc b/chrome/browser/sync/engine/syncer_thread2.cc
index 639f518..e94215e 100644
--- a/chrome/browser/sync/engine/syncer_thread2.cc
+++ b/chrome/browser/sync/engine/syncer_thread2.cc
@@ -47,6 +47,11 @@ struct SyncerThread::SyncSessionJob {
   SyncSessionJobPurpose purpose;
   base::TimeTicks scheduled_start;
   linked_ptr<sessions::SyncSession> session;
+
+  // This is the location the nudge came from. used for debugging purpose.
+  // In case of multiple nudges getting coalesced this stores the first nudge
+  // that came in.
+  tracked_objects::Location nudge_location;
 };
 
 SyncerThread::DelayProvider::DelayProvider() {}
@@ -225,7 +230,8 @@ void SyncerThread::ScheduleClearUserData() {
 }
 
 void SyncerThread::ScheduleNudge(const TimeDelta& delay,
-    NudgeSource source, const ModelTypeBitSet& types) {
+    NudgeSource source, const ModelTypeBitSet& types,
+    const tracked_objects::Location& nudge_location) {
   if (!thread_.IsRunning()) {
     NOTREACHED();
     return;
@@ -235,11 +241,12 @@ void SyncerThread::ScheduleNudge(const TimeDelta& delay,
       syncable::ModelTypePayloadMapFromBitSet(types, std::string());
   thread_.message_loop()->PostTask(FROM_HERE, NewRunnableMethod(
       this, &SyncerThread::ScheduleNudgeImpl, delay, source,
-      types_with_payloads));
+      types_with_payloads, nudge_location));
 }
 
 void SyncerThread::ScheduleNudgeWithPayloads(const TimeDelta& delay,
-    NudgeSource source, const ModelTypePayloadMap& types_with_payloads) {
+    NudgeSource source, const ModelTypePayloadMap& types_with_payloads,
+    const tracked_objects::Location& nudge_location) {
   if (!thread_.IsRunning()) {
     NOTREACHED();
     return;
@@ -247,7 +254,7 @@ void SyncerThread::ScheduleNudgeWithPayloads(const TimeDelta& delay,
 
   thread_.message_loop()->PostTask(FROM_HERE, NewRunnableMethod(
       this, &SyncerThread::ScheduleNudgeImpl, delay, source,
-      types_with_payloads));
+      types_with_payloads, nudge_location));
 }
 
 void SyncerThread::ScheduleClearUserDataImpl() {
@@ -255,11 +262,13 @@ void SyncerThread::ScheduleClearUserDataImpl() {
   SyncSession* session = new SyncSession(session_context_.get(), this,
       SyncSourceInfo(), ModelSafeRoutingInfo(),
       std::vector<ModelSafeWorker*>());
-  ScheduleSyncSessionJob(TimeDelta::FromSeconds(0), CLEAR_USER_DATA, session);
+  ScheduleSyncSessionJob(TimeDelta::FromSeconds(0), CLEAR_USER_DATA, session,
+                         FROM_HERE);
 }
 
 void SyncerThread::ScheduleNudgeImpl(const TimeDelta& delay,
-    NudgeSource source, const ModelTypePayloadMap& types_with_payloads) {
+    NudgeSource source, const ModelTypePayloadMap& types_with_payloads,
+    const tracked_objects::Location& nudge_location) {
   DCHECK_EQ(MessageLoop::current(), thread_.message_loop());
   TimeTicks rough_start = TimeTicks::Now() + delay;
   if (!ShouldRunJob(NUDGE, rough_start)) {
@@ -286,6 +295,7 @@ void SyncerThread::ScheduleNudgeImpl(const TimeDelta& delay,
       return;
 
     pending_nudge_->session->Coalesce(*session.get());
+
     if (!IsBackingOff()) {
       return;
     } else {
@@ -296,7 +306,7 @@ void SyncerThread::ScheduleNudgeImpl(const TimeDelta& delay,
       pending_nudge_.reset();
     }
   }
-  ScheduleSyncSessionJob(delay, NUDGE, session.release());
+  ScheduleSyncSessionJob(delay, NUDGE, session.release(), nudge_location);
 }
 
 // Helper to extract the routing info and workers corresponding to types in
@@ -357,20 +367,24 @@ void SyncerThread::ScheduleConfigImpl(const ModelSafeRoutingInfo& routing_info,
           syncable::ModelTypePayloadMapFromRoutingInfo(
               routing_info, std::string())),
       routing_info, workers);
-  ScheduleSyncSessionJob(TimeDelta::FromSeconds(0), CONFIGURATION, session);
+  ScheduleSyncSessionJob(TimeDelta::FromSeconds(0), CONFIGURATION, session,
+                         FROM_HERE);
 }
 
 void SyncerThread::ScheduleSyncSessionJob(const base::TimeDelta& delay,
-    SyncSessionJobPurpose purpose, sessions::SyncSession* session) {
+    SyncSessionJobPurpose purpose, sessions::SyncSession* session,
+    const tracked_objects::Location& nudge_location) {
   DCHECK_EQ(MessageLoop::current(), thread_.message_loop());
+
   SyncSessionJob job = {purpose, TimeTicks::Now() + delay,
-                        make_linked_ptr(session)};
+                        make_linked_ptr(session), nudge_location};
   if (purpose == NUDGE) {
     DCHECK(!pending_nudge_.get() || pending_nudge_->session.get() == session);
     pending_nudge_.reset(new SyncSessionJob(job));
   }
   MessageLoop::current()->PostDelayedTask(FROM_HERE, NewRunnableMethod(this,
-      &SyncerThread::DoSyncSessionJob, job), delay.InMilliseconds());
+      &SyncerThread::DoSyncSessionJob, job),
+      delay.InMilliseconds());
 }
 
 void SyncerThread::SetSyncerStepsForPurpose(SyncSessionJobPurpose purpose,
@@ -506,7 +520,7 @@ void SyncerThread::ScheduleNextSync(const SyncSessionJob& old_job) {
     // We weren't continuing and we aren't in backoff.  Schedule a normal
     // continuation.
     ScheduleNudgeImpl(TimeDelta::FromSeconds(0), NUDGE_SOURCE_CONTINUATION,
-                      old_job.session->source().types);
+                      old_job.session->source().types, FROM_HERE);
   }
 }
 
@@ -543,7 +557,7 @@ void SyncerThread::HandleConsecutiveContinuationError(
   wait_interval_.reset(new WaitInterval(WaitInterval::EXPONENTIAL_BACKOFF,
                                         length));
   SyncSessionJob job = {NUDGE, TimeTicks::Now() + length,
-                        make_linked_ptr(s)};
+                        make_linked_ptr(s), FROM_HERE};
   pending_nudge_.reset(new SyncSessionJob(job));
   wait_interval_->timer.Start(length, this, &SyncerThread::DoCanaryJob);
 }
@@ -581,9 +595,7 @@ void SyncerThread::Stop() {
 void SyncerThread::DoCanaryJob() {
   DCHECK(pending_nudge_.get());
   wait_interval_->had_nudge = false;
-  SyncSessionJob copy = {pending_nudge_->purpose,
-                         pending_nudge_->scheduled_start,
-                         pending_nudge_->session};
+  SyncSessionJob copy = *pending_nudge_;
   DoSyncSessionJob(copy);
 }
 
@@ -597,7 +609,7 @@ void SyncerThread::PollTimerCallback() {
       syncable::ModelTypePayloadMapFromRoutingInfo(r, std::string());
   SyncSourceInfo info(GetUpdatesCallerInfo::PERIODIC, types_with_payloads);
   SyncSession* s = new SyncSession(session_context_.get(), this, info, r, w);
-  ScheduleSyncSessionJob(TimeDelta::FromSeconds(0), POLL, s);
+  ScheduleSyncSessionJob(TimeDelta::FromSeconds(0), POLL, s, FROM_HERE);
 }
 
 void SyncerThread::Unthrottle() {
diff --git a/chrome/browser/sync/engine/syncer_thread2.h b/chrome/browser/sync/engine/syncer_thread2.h
index 3768456..3fbdd7f 100644
--- a/chrome/browser/sync/engine/syncer_thread2.h
+++ b/chrome/browser/sync/engine/syncer_thread2.h
@@ -68,10 +68,12 @@ class SyncerThread : public sessions::SyncSession::Delegate,
 
   // The meat and potatoes.
   void ScheduleNudge(const base::TimeDelta& delay, NudgeSource source,
-                     const syncable::ModelTypeBitSet& types);
+                     const syncable::ModelTypeBitSet& types,
+                     const tracked_objects::Location& nudge_location);
   void ScheduleNudgeWithPayloads(
       const base::TimeDelta& delay, NudgeSource source,
-      const syncable::ModelTypePayloadMap& types_with_payloads);
+      const syncable::ModelTypePayloadMap& types_with_payloads,
+      const tracked_objects::Location& nudge_location);
   void ScheduleConfig(const syncable::ModelTypeBitSet& types);
   void ScheduleClearUserData();
 
@@ -136,7 +138,8 @@ class SyncerThread : public sessions::SyncSession::Delegate,
   // Helper to assemble a job and post a delayed task to sync.
   void ScheduleSyncSessionJob(const base::TimeDelta& delay,
                               SyncSessionJobPurpose purpose,
-                              sessions::SyncSession* session);
+                              sessions::SyncSession* session,
+                              const tracked_objects::Location& nudge_location);
 
   // Invoke the Syncer to perform a sync.
   void DoSyncSessionJob(const SyncSessionJob& job);
@@ -170,7 +173,8 @@ class SyncerThread : public sessions::SyncSession::Delegate,
   void ScheduleNudgeImpl(
       const base::TimeDelta& delay,
       NudgeSource source,
-      const syncable::ModelTypePayloadMap& types_with_payloads);
+      const syncable::ModelTypePayloadMap& types_with_payloads,
+      const tracked_objects::Location& nudge_location);
   void ScheduleConfigImpl(const ModelSafeRoutingInfo& routing_info,
                           const std::vector<ModelSafeWorker*>& workers);
   void ScheduleClearUserDataImpl();
diff --git a/chrome/browser/sync/engine/syncer_thread2_unittest.cc b/chrome/browser/sync/engine/syncer_thread2_unittest.cc
index ac03cfb..02514677 100644
--- a/chrome/browser/sync/engine/syncer_thread2_unittest.cc
+++ b/chrome/browser/sync/engine/syncer_thread2_unittest.cc
@@ -99,7 +99,8 @@ class SyncerThread2Test : public testing::Test {
   bool GetBackoffAndResetTest(base::WaitableEvent* done) {
     syncable::ModelTypeBitSet nudge_types;
     syncer_thread()->Start(SyncerThread::NORMAL_MODE, NULL);
-    syncer_thread()->ScheduleNudge(zero(), NUDGE_SOURCE_LOCAL, nudge_types);
+    syncer_thread()->ScheduleNudge(zero(), NUDGE_SOURCE_LOCAL, nudge_types,
+                                   FROM_HERE);
     done->TimedWait(timeout());
     TearDown();
     done->Reset();
@@ -198,7 +199,8 @@ TEST_F(SyncerThread2Test, Nudge) {
       .WillOnce(DoAll(Invoke(sessions::test_util::SimulateSuccess),
           WithArg<0>(RecordSyncShare(&records, 1U, &done))))
       .RetiresOnSaturation();
-  syncer_thread()->ScheduleNudge(zero(), NUDGE_SOURCE_LOCAL, model_types);
+  syncer_thread()->ScheduleNudge(zero(), NUDGE_SOURCE_LOCAL, model_types,
+                                 FROM_HERE);
   done.TimedWait(timeout());
 
   EXPECT_EQ(1U, records.snapshots.size());
@@ -214,7 +216,8 @@ TEST_F(SyncerThread2Test, Nudge) {
   EXPECT_CALL(*syncer(), SyncShare(_,_,_))
       .WillOnce(DoAll(Invoke(sessions::test_util::SimulateSuccess),
           WithArg<0>(RecordSyncShare(&records2, 1U, &done))));
-  syncer_thread()->ScheduleNudge(zero(), NUDGE_SOURCE_LOCAL, model_types);
+  syncer_thread()->ScheduleNudge(zero(), NUDGE_SOURCE_LOCAL, model_types,
+                                 FROM_HERE);
   done.TimedWait(timeout());
 
   EXPECT_EQ(1U, records2.snapshots.size());
@@ -238,9 +241,12 @@ TEST_F(SyncerThread2Test, NudgeCoalescing) {
   types3[syncable::THEMES] = true;
   TimeDelta delay = TimeDelta::FromMilliseconds(20);
   TimeTicks optimal_time = TimeTicks::Now() + delay;
-  syncer_thread()->ScheduleNudge(delay, NUDGE_SOURCE_UNKNOWN, types1);
-  syncer_thread()->ScheduleNudge(zero(), NUDGE_SOURCE_LOCAL, types2);
-  syncer_thread()->ScheduleNudge(zero(), NUDGE_SOURCE_NOTIFICATION, types3);
+  syncer_thread()->ScheduleNudge(delay, NUDGE_SOURCE_UNKNOWN, types1,
+                                 FROM_HERE);
+  syncer_thread()->ScheduleNudge(zero(), NUDGE_SOURCE_LOCAL, types2,
+                                 FROM_HERE);
+  syncer_thread()->ScheduleNudge(zero(), NUDGE_SOURCE_NOTIFICATION, types3,
+                                 FROM_HERE);
   done.TimedWait(timeout());
 
   EXPECT_EQ(1U, r.snapshots.size());
@@ -255,7 +261,8 @@ TEST_F(SyncerThread2Test, NudgeCoalescing) {
   EXPECT_CALL(*syncer(), SyncShare(_,_,_))
       .WillOnce(DoAll(Invoke(sessions::test_util::SimulateSuccess),
            WithArg<0>(RecordSyncShare(&r2, 1U, &done))));
-  syncer_thread()->ScheduleNudge(zero(), NUDGE_SOURCE_NOTIFICATION, types3);
+  syncer_thread()->ScheduleNudge(zero(), NUDGE_SOURCE_NOTIFICATION, types3,
+                                 FROM_HERE);
   done.TimedWait(timeout());
   EXPECT_EQ(1U, r2.snapshots.size());
   EXPECT_TRUE(CompareModelTypeBitSetToModelTypePayloadMap(types3,
@@ -277,7 +284,7 @@ TEST_F(SyncerThread2Test, NudgeWithPayloads) {
           WithArg<0>(RecordSyncShare(&records, 1U, &done))))
       .RetiresOnSaturation();
   syncer_thread()->ScheduleNudgeWithPayloads(zero(), NUDGE_SOURCE_LOCAL,
-      model_types_with_payloads);
+      model_types_with_payloads, FROM_HERE);
   done.TimedWait(timeout());
 
   EXPECT_EQ(1U, records.snapshots.size());
@@ -293,7 +300,7 @@ TEST_F(SyncerThread2Test, NudgeWithPayloads) {
       .WillOnce(DoAll(Invoke(sessions::test_util::SimulateSuccess),
           WithArg<0>(RecordSyncShare(&records2, 1U, &done))));
   syncer_thread()->ScheduleNudgeWithPayloads(zero(), NUDGE_SOURCE_LOCAL,
-      model_types_with_payloads);
+      model_types_with_payloads, FROM_HERE);
   done.TimedWait(timeout());
 
   EXPECT_EQ(1U, records2.snapshots.size());
@@ -317,11 +324,11 @@ TEST_F(SyncerThread2Test, NudgeWithPayloadsCoalescing) {
   TimeDelta delay = TimeDelta::FromMilliseconds(20);
   TimeTicks optimal_time = TimeTicks::Now() + delay;
   syncer_thread()->ScheduleNudgeWithPayloads(delay, NUDGE_SOURCE_UNKNOWN,
-      types1);
+      types1, FROM_HERE);
   syncer_thread()->ScheduleNudgeWithPayloads(zero(), NUDGE_SOURCE_LOCAL,
-      types2);
+      types2, FROM_HERE);
   syncer_thread()->ScheduleNudgeWithPayloads(zero(), NUDGE_SOURCE_NOTIFICATION,
-      types3);
+      types3, FROM_HERE);
   done.TimedWait(timeout());
 
   EXPECT_EQ(1U, r.snapshots.size());
@@ -339,7 +346,7 @@ TEST_F(SyncerThread2Test, NudgeWithPayloadsCoalescing) {
       .WillOnce(DoAll(Invoke(sessions::test_util::SimulateSuccess),
            WithArg<0>(RecordSyncShare(&r2, 1U, &done))));
   syncer_thread()->ScheduleNudgeWithPayloads(zero(), NUDGE_SOURCE_NOTIFICATION,
-      types3);
+      types3, FROM_HERE);
   done.TimedWait(timeout());
   EXPECT_EQ(1U, r2.snapshots.size());
   EXPECT_EQ(types3, r2.snapshots[0]->source.types);
@@ -413,7 +420,8 @@ TEST_F(SyncerThread2Test, HasMoreToSync) {
       .WillOnce(Invoke(sessions::test_util::SimulateHasMoreToSync))
       .WillOnce(DoAll(Invoke(sessions::test_util::SimulateSuccess),
                       SignalEvent(&done)));
-  syncer_thread()->ScheduleNudge(zero(), NUDGE_SOURCE_LOCAL, ModelTypeBitSet());
+  syncer_thread()->ScheduleNudge(zero(), NUDGE_SOURCE_LOCAL, ModelTypeBitSet(),
+                                 FROM_HERE);
   done.TimedWait(timeout());
   // If more nudges are scheduled, they'll be waited on by TearDown, and would
   // cause our expectation to break.
@@ -431,7 +439,8 @@ TEST_F(SyncerThread2Test, ThrottlingDoesThrottle) {
       .WillOnce(WithArg<0>(sessions::test_util::SimulateThrottled(throttle)));
 
   syncer_thread()->Start(SyncerThread::NORMAL_MODE, NULL);
-  syncer_thread()->ScheduleNudge(zero(), NUDGE_SOURCE_LOCAL, types);
+  syncer_thread()->ScheduleNudge(zero(), NUDGE_SOURCE_LOCAL, types,
+                                 FROM_HERE);
   FlushLastTask(&done);
 
   syncer_thread()->Start(SyncerThread::CONFIGURATION_MODE, NULL);
@@ -476,8 +485,10 @@ TEST_F(SyncerThread2Test, ConfigurationMode) {
   syncer_thread()->Start(SyncerThread::CONFIGURATION_MODE, NULL);
   syncable::ModelTypeBitSet nudge_types;
   nudge_types[syncable::AUTOFILL] = true;
-  syncer_thread()->ScheduleNudge(zero(), NUDGE_SOURCE_LOCAL, nudge_types);
-  syncer_thread()->ScheduleNudge(zero(), NUDGE_SOURCE_LOCAL, nudge_types);
+  syncer_thread()->ScheduleNudge(zero(), NUDGE_SOURCE_LOCAL, nudge_types,
+                                 FROM_HERE);
+  syncer_thread()->ScheduleNudge(zero(), NUDGE_SOURCE_LOCAL, nudge_types,
+                                 FROM_HERE);
 
   syncable::ModelTypeBitSet config_types;
   config_types[syncable::BOOKMARKS] = true;
@@ -566,7 +577,8 @@ TEST_F(SyncerThread2Test, BackoffDropsJobs) {
 
   // We schedule a nudge with enough delay (10X poll interval) that at least
   // one or two polls would have taken place.  The nudge should succeed.
-  syncer_thread()->ScheduleNudge(poll * 10, NUDGE_SOURCE_LOCAL, types);
+  syncer_thread()->ScheduleNudge(poll * 10, NUDGE_SOURCE_LOCAL, types,
+                                 FROM_HERE);
   ASSERT_TRUE(done.TimedWait(timeout()));
   done.Reset();
 
@@ -584,8 +596,10 @@ TEST_F(SyncerThread2Test, BackoffDropsJobs) {
   FlushLastTask(&done);
 
   syncer_thread()->Start(SyncerThread::NORMAL_MODE, NULL);
-  syncer_thread()->ScheduleNudge(zero(), NUDGE_SOURCE_LOCAL, types);
-  syncer_thread()->ScheduleNudge(zero(), NUDGE_SOURCE_LOCAL, types);
+  syncer_thread()->ScheduleNudge(zero(), NUDGE_SOURCE_LOCAL, types,
+                                 FROM_HERE);
+  syncer_thread()->ScheduleNudge(zero(), NUDGE_SOURCE_LOCAL, types,
+                                 FROM_HERE);
   FlushLastTask(&done);
 }
 
@@ -683,7 +697,8 @@ TEST_F(SyncerThread2Test, SyncerSteps) {
   EXPECT_CALL(*syncer(), SyncShare(_, SYNCER_BEGIN, SYNCER_END))
       .Times(1);
   syncer_thread()->Start(SyncerThread::NORMAL_MODE, NULL);
-  syncer_thread()->ScheduleNudge(zero(), NUDGE_SOURCE_LOCAL, ModelTypeBitSet());
+  syncer_thread()->ScheduleNudge(zero(), NUDGE_SOURCE_LOCAL, ModelTypeBitSet(),
+                                 FROM_HERE);
   FlushLastTask(&done);
   syncer_thread()->Stop();
   Mock::VerifyAndClearExpectations(syncer());
@@ -729,7 +744,8 @@ TEST_F(SyncerThread2Test, StartWhenNotConnected) {
   MessageLoop cur;
   connection()->SetServerNotReachable();
   syncer_thread()->Start(SyncerThread::NORMAL_MODE, NULL);
-  syncer_thread()->ScheduleNudge(zero(), NUDGE_SOURCE_LOCAL, ModelTypeBitSet());
+  syncer_thread()->ScheduleNudge(zero(), NUDGE_SOURCE_LOCAL, ModelTypeBitSet(),
+                                 FROM_HERE);
   FlushLastTask(&done);
 
   connection()->SetServerReachable();
@@ -741,7 +757,8 @@ TEST_F(SyncerThread2Test, StartWhenNotConnected) {
   // SyncerThread.
   FlushLastTask(&done);
   EXPECT_CALL(*syncer(), SyncShare(_,_,_)).WillOnce(SignalEvent(&done));
-  syncer_thread()->ScheduleNudge(zero(), NUDGE_SOURCE_LOCAL, ModelTypeBitSet());
+  syncer_thread()->ScheduleNudge(zero(), NUDGE_SOURCE_LOCAL, ModelTypeBitSet(),
+                                 FROM_HERE);
   done.TimedWait(timeout());
 }
 
@@ -755,7 +772,8 @@ TEST_F(SyncerThread2Test, SetsPreviousRoutingInfo) {
   EXPECT_CALL(*syncer(), SyncShare(_,_,_)).Times(1);
 
   syncer_thread()->Start(SyncerThread::NORMAL_MODE, NULL);
-  syncer_thread()->ScheduleNudge(zero(), NUDGE_SOURCE_LOCAL, ModelTypeBitSet());
+  syncer_thread()->ScheduleNudge(zero(), NUDGE_SOURCE_LOCAL, ModelTypeBitSet(),
+                                 FROM_HERE);
   FlushLastTask(&done);
   syncer_thread()->Stop();
 
diff --git a/chrome/browser/sync/engine/syncer_thread_adapter.cc b/chrome/browser/sync/engine/syncer_thread_adapter.cc
index 0383b47..8a513e9 100644
--- a/chrome/browser/sync/engine/syncer_thread_adapter.cc
+++ b/chrome/browser/sync/engine/syncer_thread_adapter.cc
@@ -3,6 +3,7 @@
 // found in the LICENSE file.
 
 #include "base/time.h"
+#include "base/tracked.h"
 #include "chrome/browser/sync/engine/syncer_thread_adapter.h"
 #include "chrome/browser/sync/syncable/model_type.h"
 
@@ -77,7 +78,8 @@ s3::NudgeSource LegacyToNewSyncerThreadSource(SyncerThread::NudgeSource s) {
 }
 
 void SyncerThreadAdapter::NudgeSyncer(int milliseconds_from_now,
-                                      SyncerThread::NudgeSource source) {
+    SyncerThread::NudgeSource source,
+    const tracked_objects::Location& nudge_location) {
   if (using_new_impl_) {
     if (source == SyncerThread::kClearPrivateData) {
       new_impl_->ScheduleClearUserData();
@@ -85,7 +87,8 @@ void SyncerThreadAdapter::NudgeSyncer(int milliseconds_from_now,
     }
     new_impl_->ScheduleNudge(
         TimeDelta::FromMilliseconds(milliseconds_from_now),
-        LegacyToNewSyncerThreadSource(source), ModelTypeBitSet());
+        LegacyToNewSyncerThreadSource(source), ModelTypeBitSet(),
+        nudge_location);
   } else {
     legacy_->NudgeSyncer(milliseconds_from_now, source);
   }
@@ -94,12 +97,14 @@ void SyncerThreadAdapter::NudgeSyncer(int milliseconds_from_now,
 void SyncerThreadAdapter::NudgeSyncerWithDataTypes(
       int milliseconds_from_now,
       SyncerThread::NudgeSource source,
-      const syncable::ModelTypeBitSet& model_types) {
+      const syncable::ModelTypeBitSet& model_types,
+      const tracked_objects::Location& nudge_location) {
   DCHECK_NE(SyncerThread::kClearPrivateData, source);
   if (using_new_impl_) {
     new_impl_->ScheduleNudge(
         TimeDelta::FromMilliseconds(milliseconds_from_now),
-        LegacyToNewSyncerThreadSource(source), model_types);
+        LegacyToNewSyncerThreadSource(source), model_types,
+        nudge_location);
   } else {
     legacy_->NudgeSyncerWithDataTypes(milliseconds_from_now, source,
         model_types);
@@ -109,12 +114,14 @@ void SyncerThreadAdapter::NudgeSyncerWithDataTypes(
 void SyncerThreadAdapter::NudgeSyncerWithPayloads(
       int milliseconds_from_now,
       SyncerThread::NudgeSource source,
-      const syncable::ModelTypePayloadMap& model_types_with_payloads) {
+      const syncable::ModelTypePayloadMap& model_types_with_payloads,
+      const tracked_objects::Location& nudge_location) {
   DCHECK_NE(SyncerThread::kClearPrivateData, source);
   if (using_new_impl_) {
     new_impl_->ScheduleNudgeWithPayloads(
         TimeDelta::FromMilliseconds(milliseconds_from_now),
-        LegacyToNewSyncerThreadSource(source), model_types_with_payloads);
+        LegacyToNewSyncerThreadSource(source), model_types_with_payloads,
+        nudge_location);
   } else {
     legacy_->NudgeSyncerWithPayloads(milliseconds_from_now, source,
         model_types_with_payloads);
diff --git a/chrome/browser/sync/engine/syncer_thread_adapter.h b/chrome/browser/sync/engine/syncer_thread_adapter.h
index 5cae8e2..6b234e9 100644
--- a/chrome/browser/sync/engine/syncer_thread_adapter.h
+++ b/chrome/browser/sync/engine/syncer_thread_adapter.h
@@ -7,6 +7,7 @@
 
 #include "base/memory/ref_counted.h"
 #include "base/memory/scoped_ptr.h"
+#include "base/tracked.h"
 #include "chrome/browser/sync/engine/net/server_connection_manager.h"
 #include "chrome/browser/sync/engine/syncer_thread.h"
 #include "chrome/browser/sync/engine/syncer_thread2.h"
@@ -29,15 +30,18 @@ class SyncerThreadAdapter {
   bool RequestPause();
   bool RequestResume();
   void NudgeSyncer(int milliseconds_from_now,
-                   SyncerThread::NudgeSource source);
+                   SyncerThread::NudgeSource source,
+                   const tracked_objects::Location& nudge_location);
   void NudgeSyncerWithDataTypes(
       int milliseconds_from_now,
       SyncerThread::NudgeSource source,
-      const syncable::ModelTypeBitSet& model_types);
+      const syncable::ModelTypeBitSet& model_types,
+      const tracked_objects::Location& nudge_location);
   void NudgeSyncerWithPayloads(
       int milliseconds_from_now,
       SyncerThread::NudgeSource source,
-      const syncable::ModelTypePayloadMap& model_types_with_payloads);
+      const syncable::ModelTypePayloadMap& model_types_with_payloads,
+      const tracked_objects::Location& nudge_location);
   void SetNotificationsEnabled(bool enabled);
   void CreateSyncer(const std::string& dirname);
 
diff --git a/chrome/browser/sync/glue/sync_backend_host.cc b/chrome/browser/sync/glue/sync_backend_host.cc
index 302724f..a69a12c 100644
--- a/chrome/browser/sync/glue/sync_backend_host.cc
+++ b/chrome/browser/sync/glue/sync_backend_host.cc
@@ -456,7 +456,7 @@ void SyncBackendHost::FinishConfigureDataTypesOnFrontendLoop() {
   // TODO(tim): Remove this when we get rid of the old syncer thread.
   if (request_nudge) {
     CHECK(!using_new_syncer_thread_);
-    RequestNudge();
+    RequestNudge(FROM_HERE);
   }
 
   pending_config_mode_state_.reset();
@@ -475,9 +475,10 @@ void SyncBackendHost::EncryptDataTypes(
                        encrypted_types));
 }
 
-void SyncBackendHost::RequestNudge() {
+void SyncBackendHost::RequestNudge(const tracked_objects::Location& location) {
   core_thread_.message_loop()->PostTask(FROM_HERE,
-      NewRunnableMethod(core_.get(), &SyncBackendHost::Core::DoRequestNudge));
+      NewRunnableMethod(core_.get(), &SyncBackendHost::Core::DoRequestNudge,
+                        location));
 }
 
 void SyncBackendHost::RequestConfig(
@@ -780,7 +781,7 @@ void SyncBackendHost::Core::DoStartSyncing() {
   DCHECK(MessageLoop::current() == host_->core_thread_.message_loop());
   syncapi_->StartSyncing();
   if (deferred_nudge_for_cleanup_requested_)
-    syncapi_->RequestNudge();
+    syncapi_->RequestNudge(FROM_HERE);
   deferred_nudge_for_cleanup_requested_ = false;
 }
 
@@ -1095,8 +1096,9 @@ void SyncBackendHost::Core::StartSavingChanges() {
       this, &Core::SaveChanges);
 }
 
-void SyncBackendHost::Core::DoRequestNudge() {
-  syncapi_->RequestNudge();
+void SyncBackendHost::Core::DoRequestNudge(
+    const tracked_objects::Location& nudge_location) {
+  syncapi_->RequestNudge(nudge_location);
 }
 
 void SyncBackendHost::Core::DoRequestClearServerData() {
diff --git a/chrome/browser/sync/glue/sync_backend_host.h b/chrome/browser/sync/glue/sync_backend_host.h
index a6e6acf..b53ed05 100644
--- a/chrome/browser/sync/glue/sync_backend_host.h
+++ b/chrome/browser/sync/glue/sync_backend_host.h
@@ -336,7 +336,7 @@ class SyncBackendHost : public browser_sync::ModelSafeWorkerRegistrar {
 
     // Called on the SyncBackendHost core_thread_ to nudge/pause/resume the
     // syncer.
-    void DoRequestNudge();
+    void DoRequestNudge(const tracked_objects::Location& location);
     void DoRequestPause();
     void DoRequestResume();
     void DoRequestClearServerData();
@@ -522,7 +522,7 @@ class SyncBackendHost : public browser_sync::ModelSafeWorkerRegistrar {
   virtual void HandleInitializationCompletedOnFrontendLoop();
 
   // Posts a nudge request on the core thread.
-  virtual void RequestNudge();
+  virtual void RequestNudge(const tracked_objects::Location& location);
 
   // Posts a config request on the core thread.
   virtual void RequestConfig(const syncable::ModelTypeBitSet& added_types);
diff --git a/chrome/browser/sync/test_profile_sync_service.cc b/chrome/browser/sync/test_profile_sync_service.cc
index 2d122cc..02b44ef 100644
--- a/chrome/browser/sync/test_profile_sync_service.cc
+++ b/chrome/browser/sync/test_profile_sync_service.cc
@@ -34,6 +34,7 @@ ACTION_P(CallOnResumed, core) {
 
 namespace browser_sync {
 
+using ::testing::_;
 SyncBackendHostForProfileSyncTest::SyncBackendHostForProfileSyncTest(
     Profile* profile,
     bool set_initial_sync_ended_on_init,
@@ -48,14 +49,14 @@ SyncBackendHostForProfileSyncTest::SyncBackendHostForProfileSyncTest(
   ON_CALL(*this, RequestResume()).
       WillByDefault(testing::DoAll(CallOnResumed(core_),
                                    testing::Return(true)));
-  ON_CALL(*this, RequestNudge()).WillByDefault(
+  ON_CALL(*this, RequestNudge(_)).WillByDefault(
       testing::Invoke(this,
                       &SyncBackendHostForProfileSyncTest::
                       SimulateSyncCycleCompletedInitialSyncEnded));
 
   EXPECT_CALL(*this, RequestPause()).Times(testing::AnyNumber());
   EXPECT_CALL(*this, RequestResume()).Times(testing::AnyNumber());
-  EXPECT_CALL(*this, RequestNudge()).Times(testing::AnyNumber());
+  EXPECT_CALL(*this, RequestNudge(_)).Times(testing::AnyNumber());
 }
 
 SyncBackendHostForProfileSyncTest::~SyncBackendHostForProfileSyncTest() {}
@@ -70,7 +71,8 @@ void SyncBackendHostForProfileSyncTest::ConfigureDataTypes(
 }
 
 void SyncBackendHostForProfileSyncTest::
-    SimulateSyncCycleCompletedInitialSyncEnded() {
+    SimulateSyncCycleCompletedInitialSyncEnded(
+    const tracked_objects::Location& location) {
   syncable::ModelTypeBitSet sync_ended;
   ModelSafeRoutingInfo enabled_types;
   GetModelSafeRoutingInfo(&enabled_types);
diff --git a/chrome/browser/sync/test_profile_sync_service.h b/chrome/browser/sync/test_profile_sync_service.h
index 1af5d85..bbe1d14 100644
--- a/chrome/browser/sync/test_profile_sync_service.h
+++ b/chrome/browser/sync/test_profile_sync_service.h
@@ -42,7 +42,7 @@ class SyncBackendHostForProfileSyncTest
 
   MOCK_METHOD0(RequestPause, bool());
   MOCK_METHOD0(RequestResume, bool());
-  MOCK_METHOD0(RequestNudge, void());
+  MOCK_METHOD1(RequestNudge, void(const tracked_objects::Location&));
 
   virtual void ConfigureDataTypes(
       const DataTypeController::TypeMap& data_type_controllers,
@@ -50,7 +50,8 @@ class SyncBackendHostForProfileSyncTest
       CancelableTask* ready_task);
 
   // Called when a nudge comes in.
-  void SimulateSyncCycleCompletedInitialSyncEnded();
+  void SimulateSyncCycleCompletedInitialSyncEnded(
+      const tracked_objects::Location&);
 
   virtual sync_api::HttpPostProviderFactory* MakeHttpBridgeFactory(
       net::URLRequestContextGetter* getter);