[sync] Move and refactor CancelationSignal

The class is only used under sync/engine_impl and in fact shouldn't be
used outside, so let's move it away from base/.

While moving it, a few minor things are refactored, such as a few
functions being renamed for clarity.

Change-Id: Ibaf6e662551eeb78e2b7c7cbc88778b54cf31ee2
Bug: 1129782
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2484697Reviewed-by: Marc Treib <treib@chromium.org>
Commit-Queue: Mikel Astiz <mastiz@chromium.org>
Cr-Commit-Position: refs/heads/master@{#818459}

components/sync/BUILD.gn

@@ -91,6 +91,8 @@ static_library("rest_of_sync") {
     "engine_impl/backoff_delay_provider.h",
     "engine_impl/bookmark_update_preprocessing.cc",
     "engine_impl/bookmark_update_preprocessing.h",
+    "engine_impl/cancelation_signal.cc",
+    "engine_impl/cancelation_signal.h",
     "engine_impl/commit.cc",
     "engine_impl/commit.h",
     "engine_impl/commit_contribution.h",
@@ -397,7 +399,6 @@ source_set("unit_tests") {
   testonly = true
   sources = [
     "base/bind_to_task_runner_unittest.cc",
-    "base/cancelation_signal_unittest.cc",
     "base/client_tag_hash_unittest.cc",
     "base/enum_set_unittest.cc",
     "base/immutable_unittest.cc",
@@ -432,6 +433,7 @@ source_set("unit_tests") {
     "engine/sync_backend_registrar_unittest.cc",
     "engine_impl/backoff_delay_provider_unittest.cc",
     "engine_impl/bookmark_update_preprocessing_unittest.cc",
+    "engine_impl/cancelation_signal_unittest.cc",
     "engine_impl/commit_contribution_impl_unittest.cc",
     "engine_impl/commit_processor_unittest.cc",
     "engine_impl/cycle/nudge_tracker_unittest.cc",

components/sync/base/BUILD.gn

@@ -12,9 +12,6 @@ declare_args() {
 static_library("base") {
   sources = [
     "bind_to_task_runner.h",
-    "cancelation_observer.h",
-    "cancelation_signal.cc",
-    "cancelation_signal.h",
     "client_tag_hash.cc",
     "client_tag_hash.h",
     "data_type_histogram.cc",

components/sync/base/cancelation_observer.h

-// Copyright 2013 The Chromium Authors. All rights reserved.
-// Use of this source code is governed by a BSD-style license that can be
-// found in the LICENSE file.
-
-#ifndef COMPONENTS_SYNC_BASE_CANCELATION_OBSERVER_H_
-#define COMPONENTS_SYNC_BASE_CANCELATION_OBSERVER_H_
-
-namespace syncer {
-
-// Interface for classes that handle signals from the CancelationSignal.
-class CancelationObserver {
- public:
-  CancelationObserver() = default;
-  virtual ~CancelationObserver() = default;
-
-  // This may be called from a foreign thread while the CancelationSignal's lock
-  // is held.  The callee should avoid performing slow or blocking operations.
-  virtual void OnSignalReceived() = 0;
-};
-
-}  // namespace syncer
-
-#endif  // COMPONENTS_SYNC_BASE_CANCELATION_OBSERVER_H_

components/sync/driver/glue/sync_engine_backend.h

@@ -18,13 +18,13 @@
 #include "base/sequence_checker.h"
 #include "components/invalidation/impl/invalidation_switches.h"
 #include "components/invalidation/public/invalidation.h"
-#include "components/sync/base/cancelation_signal.h"
 #include "components/sync/base/system_encryptor.h"
 #include "components/sync/driver/glue/sync_engine_impl.h"
 #include "components/sync/engine/model_type_configurer.h"
 #include "components/sync/engine/shutdown_reason.h"
 #include "components/sync/engine/sync_encryption_handler.h"
 #include "components/sync/engine/sync_status_observer.h"
+#include "components/sync/engine_impl/cancelation_signal.h"
 #include "url/gurl.h"
 
 namespace syncer {

components/sync/engine/net/http_bridge_unittest.cc

@@ -18,7 +18,7 @@
 #include "base/test/task_environment.h"
 #include "base/threading/thread.h"
 #include "build/build_config.h"
-#include "components/sync/base/cancelation_signal.h"
+#include "components/sync/engine_impl/cancelation_signal.h"
 #include "net/http/http_response_headers.h"
 #include "net/http/http_status_code.h"
 #include "net/test/embedded_test_server/embedded_test_server.h"

components/sync/base/cancelation_signal.cc → components/sync/engine_impl/cancelation_signal.cc

@@ -2,20 +2,19 @@
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
-#include "components/sync/base/cancelation_signal.h"
+#include "components/sync/engine_impl/cancelation_signal.h"
 
 #include "base/check_op.h"
-#include "components/sync/base/cancelation_observer.h"
 
 namespace syncer {
 
-CancelationSignal::CancelationSignal() : signalled_(false), handler_(nullptr) {}
+CancelationSignal::CancelationSignal() = default;
 
 CancelationSignal::~CancelationSignal() {
   DCHECK(!handler_);
 }
 
-bool CancelationSignal::TryRegisterHandler(CancelationObserver* handler) {
+bool CancelationSignal::TryRegisterHandler(Observer* handler) {
   base::AutoLock lock(signal_lock_);
   DCHECK(!handler_);
 
@@ -26,7 +25,7 @@ bool CancelationSignal::TryRegisterHandler(CancelationObserver* handler) {
   return true;
 }
 
-void CancelationSignal::UnregisterHandler(CancelationObserver* handler) {
+void CancelationSignal::UnregisterHandler(Observer* handler) {
   base::AutoLock lock(signal_lock_);
   DCHECK_EQ(handler_, handler);
   handler_ = nullptr;
@@ -43,7 +42,7 @@ void CancelationSignal::Signal() {
 
   signalled_ = true;
   if (handler_) {
-    handler_->OnSignalReceived();
+    handler_->OnCancelationSignalReceived();
   }
 }
 

components/sync/base/cancelation_signal.h → components/sync/engine_impl/cancelation_signal.h

@@ -2,15 +2,13 @@
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
-#ifndef COMPONENTS_SYNC_BASE_CANCELATION_SIGNAL_H_
-#define COMPONENTS_SYNC_BASE_CANCELATION_SIGNAL_H_
+#ifndef COMPONENTS_SYNC_ENGINE_IMPL_CANCELATION_SIGNAL_H_
+#define COMPONENTS_SYNC_ENGINE_IMPL_CANCELATION_SIGNAL_H_
 
 #include "base/synchronization/lock.h"
 
 namespace syncer {
 
-class CancelationObserver;
-
 // This class is used to allow one thread to request that another abort and
 // return early.
 //
@@ -20,18 +18,29 @@ class CancelationObserver;
 // periodically check the value of IsSignalled() to see if it should return
 // early.
 //
-// The receiving task may also choose to register an CancelationObserver whose
-// OnSignalReceived() method will be executed on the signaller's thread when
-// Signal() is called.  This may be used for sending an early Signal() to a
-// WaitableEvent.  The registration of the handler is necessarily racy.  If
-// Signal() is executes before TryRegisterHandler(), TryRegisterHandler() will
-// not perform any registration and return false.  That function's caller must
-// handle this case.
+// The receiving task may also choose to register an observer whose
+// OnCancelationSignalReceived() method will be executed on the signaller's
+// thread when Signal() is called.  This may be used for sending an early
+// Signal() to a WaitableEvent.  The registration of the handler is necessarily
+// racy.  If Signal() is executes before TryRegisterHandler(),
+// TryRegisterHandler() will not perform any registration and return false. That
+// function's caller must handle this case.
 //
 // This class supports only one handler, though it could easily support multiple
 // observers if we found a use case for such a feature.
 class CancelationSignal {
  public:
+  class Observer {
+   public:
+    Observer() = default;
+    virtual ~Observer() = default;
+
+    // This may be called from a foreign thread while the CancelationSignal's
+    // lock is held.  The callee should avoid performing slow or blocking
+    // operations.
+    virtual void OnCancelationSignalReceived() = 0;
+  };
+
   CancelationSignal();
   ~CancelationSignal();
 
@@ -42,16 +51,16 @@ class CancelationSignal {
   //
   // If the registration was successful, the handler must be unregistered with
   // UnregisterHandler before this CancelationSignal is destroyed.
-  bool TryRegisterHandler(CancelationObserver* handler);
+  bool TryRegisterHandler(Observer* handler);
 
   // Unregisters the abort handler.
-  void UnregisterHandler(CancelationObserver* handler);
+  void UnregisterHandler(Observer* handler);
 
   // Returns true if Signal() has been called.
   bool IsSignalled();
 
-  // Sets the stop_requested_ flag and calls the OnSignalReceived() method of
-  // the registered handler, if there is one registered at the time.
+  // Sets the stop_requested_ flag and calls the OnCancelationSignalReceived()
+  // method of the registered handler, if there is one registered at the time.
   // SignalReceived() will be called with the |signal_lock_| held.
   void Signal();
 
@@ -60,12 +69,12 @@ class CancelationSignal {
   base::Lock signal_lock_;
 
   // True if Signal() has been invoked.
-  bool signalled_;
+  bool signalled_ = false;
 
   // The registered abort handler.  May be null.
-  CancelationObserver* handler_;
+  Observer* handler_ = nullptr;
 };
 
 }  // namespace syncer
 
-#endif  // COMPONENTS_SYNC_BASE_CANCELATION_SIGNAL_H_
+#endif  // COMPONENTS_SYNC_ENGINE_IMPL_CANCELATION_SIGNAL_H_

components/sync/base/cancelation_signal_unittest.cc → components/sync/engine_impl/cancelation_signal_unittest.cc

@@ -2,7 +2,7 @@
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
-#include "components/sync/base/cancelation_signal.h"
+#include "components/sync/engine_impl/cancelation_signal.h"
 
 #include "base/bind.h"
 #include "base/single_thread_task_runner.h"
@@ -11,12 +11,11 @@
 #include "base/threading/platform_thread.h"
 #include "base/threading/thread.h"
 #include "base/time/time.h"
-#include "components/sync/base/cancelation_observer.h"
 #include "testing/gtest/include/gtest/gtest.h"
 
 namespace syncer {
 
-class BlockingTask : public CancelationObserver {
+class BlockingTask : public CancelationSignal::Observer {
  public:
   explicit BlockingTask(CancelationSignal* cancel_signal);
   ~BlockingTask() override;
@@ -32,9 +31,9 @@ class BlockingTask : public CancelationObserver {
   void Run(base::WaitableEvent* task_start_signal,
            base::WaitableEvent* task_done_signal);
 
-  // Implementation of CancelationObserver.
+  // Implementation of CancelationSignal::Observer.
   // Wakes up the thread blocked in Run().
-  void OnSignalReceived() override;
+  void OnCancelationSignalReceived() override;
 
   // Checks if we ever did successfully start waiting for |event_|.  Be careful
   // with this.  The flag itself is thread-unsafe, and the event that flips it
@@ -81,7 +80,7 @@ void BlockingTask::Run(base::WaitableEvent* task_start_signal,
   task_done_signal->Signal();
 }
 
-void BlockingTask::OnSignalReceived() {
+void BlockingTask::OnCancelationSignalReceived() {
   event_.Signal();
 }
 
@@ -150,12 +149,13 @@ bool CancelationSignalTest::VerifyTaskNotStarted() {
   return !blocking_task_.WasStarted();
 }
 
-class FakeCancelationObserver : public CancelationObserver {
-  void OnSignalReceived() override {}
+class FakeObserver : public CancelationSignal::Observer {
+ public:
+  void OnCancelationSignalReceived() override {}
 };
 
 TEST(CancelationSignalTest_SingleThread, CheckFlags) {
-  FakeCancelationObserver observer;
+  FakeObserver observer;
   CancelationSignal signal;
 
   EXPECT_FALSE(signal.IsSignalled());

components/sync/engine_impl/model_type_registry_unittest.cc

@@ -10,9 +10,9 @@
 #include "base/deferred_sequenced_task_runner.h"
 #include "base/test/gtest_util.h"
 #include "base/test/task_environment.h"
-#include "components/sync/base/cancelation_signal.h"
 #include "components/sync/engine/data_type_activation_response.h"
 #include "components/sync/engine/fake_model_type_processor.h"
+#include "components/sync/engine_impl/cancelation_signal.h"
 #include "components/sync/protocol/model_type_state.pb.h"
 #include "components/sync/test/engine/mock_nudge_handler.h"
 #include "components/sync/test/fake_sync_encryption_handler.h"

components/sync/engine_impl/model_type_worker.cc

@@ -19,7 +19,6 @@
 #include "base/strings/stringprintf.h"
 #include "base/threading/thread_restrictions.h"
 #include "base/trace_event/memory_usage_estimator.h"
-#include "components/sync/base/cancelation_signal.h"
 #include "components/sync/base/client_tag_hash.h"
 #include "components/sync/base/data_type_histogram.h"
 #include "components/sync/base/hash_util.h"
@@ -28,6 +27,7 @@
 #include "components/sync/base/unique_position.h"
 #include "components/sync/engine/model_type_processor.h"
 #include "components/sync/engine_impl/bookmark_update_preprocessing.h"
+#include "components/sync/engine_impl/cancelation_signal.h"
 #include "components/sync/engine_impl/commit_contribution.h"
 #include "components/sync/engine_impl/commit_contribution_impl.h"
 #include "components/sync/engine_impl/cycle/entity_change_metric_recording.h"
@@ -392,7 +392,7 @@ std::unique_ptr<CommitContribution> ModelTypeWorker::GetContribution(
   model_type_processor_->GetLocalChanges(
       max_entries,
       base::BindOnce(&GetLocalChangesRequest::SetResponse, request));
-  request->WaitForResponse();
+  request->WaitForResponseOrCancelation();
   CommitRequestDataList response;
   if (!request->WasCancelled())
     response = request->ExtractResponse();
@@ -632,11 +632,11 @@ GetLocalChangesRequest::GetLocalChangesRequest(
 
 GetLocalChangesRequest::~GetLocalChangesRequest() {}
 
-void GetLocalChangesRequest::OnSignalReceived() {
+void GetLocalChangesRequest::OnCancelationSignalReceived() {
   response_accepted_.Signal();
 }
 
-void GetLocalChangesRequest::WaitForResponse() {
+void GetLocalChangesRequest::WaitForResponseOrCancelation() {
   if (!cancelation_signal_->TryRegisterHandler(this)) {
     return;
   }

components/sync/engine_impl/model_type_worker.h

@@ -16,12 +16,12 @@
 #include "base/memory/weak_ptr.h"
 #include "base/sequence_checker.h"
 #include "base/synchronization/waitable_event.h"
-#include "components/sync/base/cancelation_observer.h"
 #include "components/sync/base/model_type.h"
 #include "components/sync/base/passphrase_enums.h"
 #include "components/sync/engine/commit_and_get_updates_types.h"
 #include "components/sync/engine/commit_queue.h"
 #include "components/sync/engine/sync_encryption_handler.h"
+#include "components/sync/engine_impl/cancelation_signal.h"
 #include "components/sync/engine_impl/commit_contributor.h"
 #include "components/sync/engine_impl/nudge_handler.h"
 #include "components/sync/engine_impl/update_handler.h"
@@ -252,30 +252,30 @@ class ModelTypeWorker : public UpdateHandler,
 // model_type_processor_->GetLocalChanges(
 //     max_entries,
 //     base::Bind(&GetLocalChangesRequest::SetResponse, request));
-// request->WaitForResponse();
+// request->WaitForResponseOrCancelation();
 // CommitRequestDataList response;
 // if (!request->WasCancelled())
 //   response = request->ExtractResponse();
 class GetLocalChangesRequest
     : public base::RefCountedThreadSafe<GetLocalChangesRequest>,
-      public CancelationObserver {
+      public CancelationSignal::Observer {
  public:
   explicit GetLocalChangesRequest(CancelationSignal* cancelation_signal);
 
-  // CancelationObserver implementation.
-  void OnSignalReceived() override;
+  // CancelationSignal::Observer implementation.
+  void OnCancelationSignalReceived() override;
 
   // Blocks current thread until either SetResponse is called or
   // cancelation_signal_ is signaled.
-  void WaitForResponse();
+  void WaitForResponseOrCancelation();
 
-  // SetResponse takes ownership of |local_changes| and unblocks WaitForResponse
-  // call. It is called by model type through callback passed to
-  // GetLocalChanges.
+  // SetResponse takes ownership of |local_changes| and unblocks
+  // WaitForResponseOrCancelation call. It is called by model type through
+  // callback passed to GetLocalChanges.
   void SetResponse(CommitRequestDataList&& local_changes);
 
-  // Checks if WaitForResponse was canceled through CancelationSignal. When
-  // returns true calling ExtractResponse is unsafe.
+  // Checks if WaitForResponseOrCancelation was canceled through
+  // CancelationSignal. When returns true calling ExtractResponse is unsafe.
   bool WasCancelled();
 
   // Returns response set by SetResponse().

components/sync/engine_impl/model_type_worker_unittest.cc

@@ -14,10 +14,10 @@
 #include "base/strings/stringprintf.h"
 #include "base/test/metrics/histogram_tester.h"
 #include "base/threading/thread.h"
-#include "components/sync/base/cancelation_signal.h"
 #include "components/sync/base/client_tag_hash.h"
 #include "components/sync/base/unique_position.h"
 #include "components/sync/engine/model_type_processor.h"
+#include "components/sync/engine_impl/cancelation_signal.h"
 #include "components/sync/engine_impl/commit_contribution.h"
 #include "components/sync/engine_impl/cycle/entity_change_metric_recording.h"
 #include "components/sync/engine_impl/cycle/status_controller.h"
@@ -1672,7 +1672,8 @@ class GetLocalChangesRequestTest : public testing::Test {
 
   scoped_refptr<GetLocalChangesRequest> MakeRequest();
 
-  void BlockingWaitForResponse(scoped_refptr<GetLocalChangesRequest> request);
+  void BlockingWaitForResponseOrCancelation(
+      scoped_refptr<GetLocalChangesRequest> request);
   void ScheduleBlockingWait(scoped_refptr<GetLocalChangesRequest> request);
 
  protected:
@@ -1704,10 +1705,10 @@ GetLocalChangesRequestTest::MakeRequest() {
   return base::MakeRefCounted<GetLocalChangesRequest>(&cancelation_signal_);
 }
 
-void GetLocalChangesRequestTest::BlockingWaitForResponse(
+void GetLocalChangesRequestTest::BlockingWaitForResponseOrCancelation(
     scoped_refptr<GetLocalChangesRequest> request) {
   start_event_.Signal();
-  request->WaitForResponse();
+  request->WaitForResponseOrCancelation();
   done_event_.Signal();
 }
 
@@ -1715,15 +1716,16 @@ void GetLocalChangesRequestTest::ScheduleBlockingWait(
     scoped_refptr<GetLocalChangesRequest> request) {
   blocking_thread_.task_runner()->PostTask(
       FROM_HERE,
-      base::BindOnce(&GetLocalChangesRequestTest::BlockingWaitForResponse,
-                     base::Unretained(this), request));
+      base::BindOnce(
+          &GetLocalChangesRequestTest::BlockingWaitForResponseOrCancelation,
+          base::Unretained(this), request));
 }
 
 // Tests that request doesn't block when cancelation signal is already signaled.
 TEST_F(GetLocalChangesRequestTest, CancelationSignaledBeforeRequest) {
   cancelation_signal_.Signal();
   auto request = MakeRequest();
-  request->WaitForResponse();
+  request->WaitForResponseOrCancelation();
   EXPECT_TRUE(request->WasCancelled());
 }
 

components/sync/engine_impl/net/server_connection_manager.cc

@@ -10,7 +10,7 @@
 
 #include "base/metrics/histogram.h"
 #include "build/build_config.h"
-#include "components/sync/base/cancelation_signal.h"
+#include "components/sync/engine_impl/cancelation_signal.h"
 #include "components/sync/engine_impl/net/url_translator.h"
 #include "components/sync/engine_impl/syncer.h"
 #include "components/sync/protocol/sync.pb.h"

components/sync/engine_impl/net/sync_server_connection_manager.cc

@@ -10,10 +10,9 @@
 
 #include "base/bind.h"
 #include "base/callback_helpers.h"
-#include "components/sync/base/cancelation_observer.h"
-#include "components/sync/base/cancelation_signal.h"
 #include "components/sync/engine/net/http_post_provider_factory.h"
 #include "components/sync/engine/net/http_post_provider_interface.h"
+#include "components/sync/engine_impl/cancelation_signal.h"
 #include "net/base/net_errors.h"
 #include "net/http/http_status_code.h"
 
@@ -22,7 +21,7 @@ namespace {
 
 // This provides HTTP Post functionality through the interface provided
 // by the application hosting the syncer backend.
-class Connection : public CancelationObserver {
+class Connection : public CancelationSignal::Observer {
  public:
   // All pointers must not be null and must outlive this object.
   Connection(HttpPostProviderFactory* factory,
@@ -35,8 +34,8 @@ class Connection : public CancelationObserver {
   bool ReadBufferResponse(std::string* buffer_out, HttpResponse* response);
   bool ReadDownloadResponse(HttpResponse* response, std::string* buffer_out);
 
-  // CancelationObserver overrides.
-  void OnSignalReceived() override;
+  // CancelationSignal::Observer overrides.
+  void OnCancelationSignalReceived() override;
 
  private:
   int ReadResponse(std::string* out_buffer, int length) const;
@@ -154,7 +153,7 @@ int Connection::ReadResponse(std::string* out_buffer, int length) const {
   return bytes_read;
 }
 
-void Connection::OnSignalReceived() {
+void Connection::OnCancelationSignalReceived() {
   DCHECK(post_provider_);
   post_provider_->Abort();
 }

components/sync/engine_impl/net/sync_server_connection_manager_unittest.cc

@@ -11,9 +11,9 @@
 #include "base/test/test_timeouts.h"
 #include "base/threading/thread.h"
 #include "base/time/time.h"
-#include "components/sync/base/cancelation_signal.h"
 #include "components/sync/engine/net/http_post_provider_factory.h"
 #include "components/sync/engine/net/http_post_provider_interface.h"
+#include "components/sync/engine_impl/cancelation_signal.h"
 #include "net/base/net_errors.h"
 #include "testing/gtest/include/gtest/gtest.h"
 

components/sync/engine_impl/sync_manager_impl.cc

@@ -15,7 +15,6 @@
 #include "base/metrics/histogram_macros.h"
 #include "base/threading/sequenced_task_runner_handle.h"
 #include "base/values.h"
-#include "components/sync/base/cancelation_signal.h"
 #include "components/sync/base/invalidation_interface.h"
 #include "components/sync/base/model_type.h"
 #include "components/sync/engine/configure_reason.h"
@@ -23,6 +22,7 @@
 #include "components/sync/engine/engine_util.h"
 #include "components/sync/engine/net/http_post_provider_factory.h"
 #include "components/sync/engine/polling_constants.h"
+#include "components/sync/engine_impl/cancelation_signal.h"
 #include "components/sync/engine_impl/loopback_server/loopback_connection_manager.h"
 #include "components/sync/engine_impl/model_type_connector_proxy.h"
 #include "components/sync/engine_impl/net/sync_server_connection_manager.h"

components/sync/engine_impl/sync_manager_impl_unittest.cc

@@ -21,7 +21,6 @@
 #include "base/test/task_environment.h"
 #include "base/test/values_test_util.h"
 #include "base/values.h"
-#include "components/sync/base/cancelation_signal.h"
 #include "components/sync/base/client_tag_hash.h"
 #include "components/sync/base/extensions_activity.h"
 #include "components/sync/base/model_type.h"
@@ -32,6 +31,7 @@
 #include "components/sync/engine/net/http_post_provider_interface.h"
 #include "components/sync/engine/polling_constants.h"
 #include "components/sync/engine/test_engine_components_factory.h"
+#include "components/sync/engine_impl/cancelation_signal.h"
 #include "components/sync/engine_impl/cycle/sync_cycle.h"
 #include "components/sync/engine_impl/sync_scheduler.h"
 #include "components/sync/js/js_event_handler.h"

components/sync/engine_impl/sync_scheduler_impl_unittest.cc

@@ -18,13 +18,13 @@
 #include "base/test/task_environment.h"
 #include "base/test/test_timeouts.h"
 #include "base/threading/sequenced_task_runner_handle.h"
-#include "components/sync/base/cancelation_signal.h"
 #include "components/sync/base/extensions_activity.h"
 #include "components/sync/base/model_type_test_util.h"
 #include "components/sync/engine/data_type_activation_response.h"
 #include "components/sync/engine/fake_model_type_processor.h"
 #include "components/sync/engine/sync_engine_switches.h"
 #include "components/sync/engine_impl/backoff_delay_provider.h"
+#include "components/sync/engine_impl/cancelation_signal.h"
 #include "components/sync/engine_impl/cycle/test_util.h"
 #include "components/sync/test/callback_counter.h"
 #include "components/sync/test/engine/mock_connection_manager.h"

components/sync/engine_impl/syncer.cc

@@ -11,8 +11,8 @@
 #include "base/logging.h"
 #include "base/metrics/histogram_functions.h"
 #include "base/trace_event/trace_event.h"
-#include "components/sync/base/cancelation_signal.h"
 #include "components/sync/engine/sync_engine_switches.h"
+#include "components/sync/engine_impl/cancelation_signal.h"
 #include "components/sync/engine_impl/commit.h"
 #include "components/sync/engine_impl/commit_processor.h"
 #include "components/sync/engine_impl/cycle/nudge_tracker.h"

components/sync/engine_impl/syncer_unittest.cc

@@ -25,13 +25,13 @@
 #include "base/test/task_environment.h"
 #include "base/time/time.h"
 #include "build/build_config.h"
-#include "components/sync/base/cancelation_signal.h"
 #include "components/sync/base/client_tag_hash.h"
 #include "components/sync/base/extensions_activity.h"
 #include "components/sync/base/time.h"
 #include "components/sync/engine/data_type_activation_response.h"
 #include "components/sync/engine/forwarding_model_type_processor.h"
 #include "components/sync/engine_impl/backoff_delay_provider.h"
+#include "components/sync/engine_impl/cancelation_signal.h"
 #include "components/sync/engine_impl/cycle/mock_debug_info_getter.h"
 #include "components/sync/engine_impl/cycle/sync_cycle_context.h"
 #include "components/sync/engine_impl/net/server_connection_manager.h"