sync: Drop fully datatype throttled sync jobs rather than saving them.

sync/engine/sync_scheduler_impl.cc

 // Copyright (c) 2012 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.
 
 #include "sync/engine/sync_scheduler_impl.h"
 
 #include <algorithm>
 #include <cstring>
 
 #include "base/auto_reset.h"
@@ skipping 411 matching lines @@
       requested_types.Put(i->first);
     }
 
     // If all types are throttled, do not CONTINUE.  Today, we don't treat
     // a per-datatype "unthrottle" event as something that should force a
     // canary job. For this reason, there's no good time to reschedule this job
     // to run -- we'll lazily wait for an independent event to trigger a sync.
     // Note that there may already be such an event if we're in a WaitInterval,
     // so we can retry it then.
     if (!requested_types.Empty() && throttled_types.HasAll(requested_types))
-      return SAVE;
+      return DROP;  // TODO(tim): Don't drop. http://crbug.com/177659
   }
 
   if (wait_interval_.get())
     return DecideWhileInWaitInterval(job);
 
   if (mode_ == CONFIGURATION_MODE) {
     if (job.purpose() == SyncSessionJob::NUDGE)
       return SAVE;  // Running requires a mode switch.
     else if (job.purpose() == SyncSessionJob::CONFIGURATION)
       return CONTINUE;
@@ skipping 748 matching lines @@
 
 #undef SDVLOG_LOC
 
 #undef SDVLOG
 
 #undef SLOG
 
 #undef ENUM_CASE
 
 }  // namespace syncer