Lock-free shutdown of profile sync service. Changes include:

* Disconnect non-frontend processor/associator to stop accessing directory
so that sync backend can be shut down without waiting.
* Change non-frontend controller so that creation/destruction of 
processor/associator doesn't depend on valid controller. So
scoped wait on stopping controller can be removed.
* Move sync thread to PSS. It's created when starting first backend and 
destroyed on last browser thread.

BUG=19757

Committed: https://src.chromium.org/viewvc/chrome?view=rev&revision=210333

Committed: https://src.chromium.org/viewvc/chrome?view=rev&revision=210955

Committed: https://src.chromium.org/viewvc/chrome?view=rev&revision=213642

Review URL: https://chromiumcodereview.appspot.com/16770005

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@214500 0039d316-1c4b-4281-b951-d872f2087c98

3 files changed, 13 insertions, 11 deletions

diff --git a/sync/sessions/sync_session_context.cc b/sync/sessions/sync_session_context.cc
index c48c32b..98ab5f0 100644
--- a/sync/sessions/sync_session_context.cc
+++ b/sync/sessions/sync_session_context.cc
@@ -5,7 +5,7 @@
 #include "sync/sessions/sync_session_context.h"
 
 #include "sync/sessions/debug_info_getter.h"
-#include "sync/util/extensions_activity_monitor.h"
+#include "sync/util/extensions_activity.h"
 
 namespace syncer {
 namespace sessions {
@@ -17,7 +17,7 @@ SyncSessionContext::SyncSessionContext(
     ServerConnectionManager* connection_manager,
     syncable::Directory* directory,
     const std::vector<ModelSafeWorker*>& workers,
-    ExtensionsActivityMonitor* extensions_activity_monitor,
+    ExtensionsActivity* extensions_activity,
     const std::vector<SyncEngineEventListener*>& listeners,
     DebugInfoGetter* debug_info_getter,
     TrafficRecorder* traffic_recorder,
@@ -26,7 +26,7 @@ SyncSessionContext::SyncSessionContext(
     const std::string& invalidator_client_id)
     : connection_manager_(connection_manager),
       directory_(directory),
-      extensions_activity_monitor_(extensions_activity_monitor),
+      extensions_activity_(extensions_activity),
       notifications_enabled_(false),
       max_commit_batch_size_(kDefaultMaxCommitBatchSize),
       debug_info_getter_(debug_info_getter),
diff --git a/sync/sessions/sync_session_context.h b/sync/sessions/sync_session_context.h
index 7617095..718cc6c 100644
--- a/sync/sessions/sync_session_context.h
+++ b/sync/sessions/sync_session_context.h
@@ -32,7 +32,7 @@
 
 namespace syncer {
 
-class ExtensionsActivityMonitor;
+class ExtensionsActivity;
 class ServerConnectionManager;
 
 namespace syncable {
@@ -50,7 +50,7 @@ class SYNC_EXPORT_PRIVATE SyncSessionContext {
   SyncSessionContext(ServerConnectionManager* connection_manager,
                      syncable::Directory* directory,
                      const std::vector<ModelSafeWorker*>& workers,
-                     ExtensionsActivityMonitor* extensions_activity_monitor,
+                     ExtensionsActivity* extensions_activity,
                      const std::vector<SyncEngineEventListener*>& listeners,
                      DebugInfoGetter* debug_info_getter,
                      TrafficRecorder* traffic_recorder,
@@ -79,8 +79,8 @@ class SYNC_EXPORT_PRIVATE SyncSessionContext {
     return workers_;
   }
 
-  ExtensionsActivityMonitor* extensions_monitor() {
-    return extensions_activity_monitor_;
+  ExtensionsActivity* extensions_activity() {
+    return extensions_activity_.get();
   }
 
   DebugInfoGetter* debug_info_getter() {
@@ -159,7 +159,7 @@ class SYNC_EXPORT_PRIVATE SyncSessionContext {
 
   // We use this to stuff extensions activity into CommitMessages so the server
   // can correlate commit traffic with extension-related bookmark mutations.
-  ExtensionsActivityMonitor* extensions_activity_monitor_;
+  scoped_refptr<ExtensionsActivity> extensions_activity_;
 
   // Kept up to date with talk events to determine whether notifications are
   // enabled. True only if the notification channel is authorized and open.
diff --git a/sync/sessions/sync_session_unittest.cc b/sync/sessions/sync_session_unittest.cc
index 4acee56..979ddbd 100644
--- a/sync/sessions/sync_session_unittest.cc
+++ b/sync/sessions/sync_session_unittest.cc
@@ -16,7 +16,7 @@
 #include "sync/syncable/syncable_write_transaction.h"
 #include "sync/test/engine/fake_model_worker.h"
 #include "sync/test/engine/test_directory_setter_upper.h"
-#include "sync/test/fake_extensions_activity_monitor.h"
+#include "sync/util/extensions_activity.h"
 #include "testing/gtest/include/gtest/gtest.h"
 
 namespace syncer {
@@ -38,6 +38,8 @@ class SyncSessionTest : public testing::Test,
   }
 
   virtual void SetUp() {
+    extensions_activity_ = new ExtensionsActivity();
+
     routes_.clear();
     routes_[BOOKMARKS] = GROUP_UI;
     routes_[AUTOFILL] = GROUP_DB;
@@ -60,7 +62,7 @@ class SyncSessionTest : public testing::Test,
             NULL,
             NULL,
             workers,
-            &extensions_activity_monitor_,
+            extensions_activity_.get(),
             std::vector<SyncEngineEventListener*>(),
             NULL,
             NULL,
@@ -146,7 +148,7 @@ class SyncSessionTest : public testing::Test,
   scoped_ptr<SyncSessionContext> context_;
   std::vector<scoped_refptr<ModelSafeWorker> > workers_;
   ModelSafeRoutingInfo routes_;
-  FakeExtensionsActivityMonitor extensions_activity_monitor_;
+  scoped_refptr<ExtensionsActivity> extensions_activity_;
 };
 
 TEST_F(SyncSessionTest, MoreToDownloadIfDownloadFailed) {