[Sync] Move //components/sync to the syncer namespace, take 2.

components/sync/engine_impl/syncer.cc

Index: components/sync/engine_impl/syncer.cc
diff --git a/components/sync/engine_impl/syncer.cc b/components/sync/engine_impl/syncer.cc
index f4706a9ffd529573e3b2eec379019663905051cd..2fbe96ed5d0cb64752d884a2a99eb8de800f233a 100644
--- a/components/sync/engine_impl/syncer.cc
+++ b/components/sync/engine_impl/syncer.cc
@@ -41,7 +41,7 @@ static const bool kCreateMobileBookmarksFolder = true;
 static const bool kCreateMobileBookmarksFolder = false;
 #endif
 
-Syncer::Syncer(syncer::CancelationSignal* cancelation_signal)
+Syncer::Syncer(CancelationSignal* cancelation_signal)
     : cancelation_signal_(cancelation_signal), is_syncing_(false) {}
 
 Syncer::~Syncer() {}