[Sync] Clean up intra-sync DEPS significantly.

components/sync/engine/commit_queue.h

Index: components/sync/engine/commit_queue.h
diff --git a/components/sync/engine_impl/commit_queue.h b/components/sync/engine/commit_queue.h
similarity index 78%
rename from components/sync/engine_impl/commit_queue.h
rename to components/sync/engine/commit_queue.h
index cbe90eb7114603dd7822db293aa1fc6e14ffe241..58cd2f6c2d05503fb6f0a77eecd30aab22476156 100644
--- a/components/sync/engine_impl/commit_queue.h
+++ b/components/sync/engine/commit_queue.h
@@ -2,8 +2,8 @@
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
-#ifndef COMPONENTS_SYNC_ENGINE_IMPL_COMMIT_QUEUE_H_
-#define COMPONENTS_SYNC_ENGINE_IMPL_COMMIT_QUEUE_H_
+#ifndef COMPONENTS_SYNC_ENGINE_COMMIT_QUEUE_H_
+#define COMPONENTS_SYNC_ENGINE_COMMIT_QUEUE_H_
 
 #include "components/sync/core/non_blocking_sync_common.h"
 
@@ -21,4 +21,4 @@ class CommitQueue {
 
 }  // namespace syncer_v2
 
-#endif  // COMPONENTS_SYNC_ENGINE_IMPL_COMMIT_QUEUE_H_
+#endif  // COMPONENTS_SYNC_ENGINE_COMMIT_QUEUE_H_