Revert 222154 "sync: Gracefully handle very early shutdown"

Makes tests very Flaky.
http://test-results.appspot.com/dashboards/flakiness_dashboard.html#group=%40ToT%20Chromium&testType=sync_integration_tests&tests=TwoClientPasswordsSyncTest.SetPassphraseAndThenSetupSync

Can reproduce on local build.


> sync: Gracefully handle very early shutdown
> 
> Introduce a new object to communicate cross-thread cancellation signals.
> This new object, the CancellationSignal, is protected by a lock.  It
> allows the receiving thread to query whether or not a stop has been
> requested.  It also allows the receiving thread to safely register a
> cross-thread callback to be invoked immediately when a stop is
> requested.
> 
> This class is used to reimplement the UI thread to sync thread early
> shutdown signal.  Previously, the UI thread would try to call in to
> objects owned by the sync thread.  This required a workaround if the
> signal arrived very early, since we couldn't guarantee the sync thread
> had actually created those objects until later.  The CancellationSignal
> is owned by the UI thread, so it is safe to call its RequestStop() at
> any point during sync initialization.  The sync thread will receive the
> signal when it's ready.
> 
> The new scheme has a few advantages over the old:
> - Thread ownership is simpler.  The SyncBackendHost::Core, SyncManager,
>   ServerConnectionManager, SyncScheduler and Syncer can now claim that
>   all their member functions run on the sync thread.
> - We no longer need to implement special case logic for when a shutdown
>   is requested before the SyncManager has initialized.
> - In a future CL, we can take advantage of the fact that we no longer
>   require the special case to reduce inter-thread communication during
>   sync startup.  This will make startup simpler and, in some cases,
>   improve sync startup time by as much as a few hundred milliseconds.
> - This will make it easier to address crbug.com/236451.
> 
> BUG=236451
> 
> Review URL: https://chromiumcodereview.appspot.com/23189021

TBR=rlarocque@chromium.org

Review URL: https://codereview.chromium.org/23658030

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@222205 0039d316-1c4b-4281-b951-d872f2087c98

4 files changed, 3 insertions, 4 deletions

diff --git a/sync/test/engine/fake_sync_scheduler.cc b/sync/test/engine/fake_sync_scheduler.cc
index 5d45494..1e0c7e8 100644
--- a/sync/test/engine/fake_sync_scheduler.cc
+++ b/sync/test/engine/fake_sync_scheduler.cc
@@ -13,7 +13,7 @@ FakeSyncScheduler::~FakeSyncScheduler() {}
 void FakeSyncScheduler::Start(Mode mode) {
 }
 
-void FakeSyncScheduler::Stop() {
+void FakeSyncScheduler::RequestStop() {
 }
 
 void FakeSyncScheduler::ScheduleLocalNudge(
diff --git a/sync/test/engine/fake_sync_scheduler.h b/sync/test/engine/fake_sync_scheduler.h
index 95bdfa9..11a63cc 100644
--- a/sync/test/engine/fake_sync_scheduler.h
+++ b/sync/test/engine/fake_sync_scheduler.h
@@ -20,7 +20,7 @@ class FakeSyncScheduler : public SyncScheduler {
   virtual ~FakeSyncScheduler();
 
   virtual void Start(Mode mode) OVERRIDE;
-  virtual void Stop() OVERRIDE;
+  virtual void RequestStop() OVERRIDE;
   virtual void ScheduleLocalNudge(
       const base::TimeDelta& desired_delay,
       ModelTypeSet types,
diff --git a/sync/test/engine/mock_connection_manager.cc b/sync/test/engine/mock_connection_manager.cc
index 6668638..5bf2b4b 100644
--- a/sync/test/engine/mock_connection_manager.cc
+++ b/sync/test/engine/mock_connection_manager.cc
@@ -34,7 +34,7 @@ static char kValidAuthToken[] = "AuthToken";
 static char kCacheGuid[] = "kqyg7097kro6GSUod+GSg==";
 
 MockConnectionManager::MockConnectionManager(syncable::Directory* directory)
-    : ServerConnectionManager("unused", 0, false, false, NULL),
+    : ServerConnectionManager("unused", 0, false, false),
       server_reachable_(true),
       conflict_all_commits_(false),
       conflict_n_commits_(0),
diff --git a/sync/test/engine/mock_connection_manager.h b/sync/test/engine/mock_connection_manager.h
index d82a1bf..83de59a 100644
--- a/sync/test/engine/mock_connection_manager.h
+++ b/sync/test/engine/mock_connection_manager.h
@@ -15,7 +15,6 @@
 #include "base/callback.h"
 #include "base/compiler_specific.h"
 #include "base/memory/scoped_vector.h"
-#include "base/synchronization/lock.h"
 #include "sync/engine/net/server_connection_manager.h"
 #include "sync/internal_api/public/base/model_type.h"
 #include "sync/internal_api/public/base/unique_position.h"