Never lock the Pepper proxy lock on the IO thread

ppapi/shared_impl/callback_tracker.cc

 // Copyright (c) 2010 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 "ppapi/shared_impl/callback_tracker.h"
 
 #include <algorithm>
 
 #include "base/bind.h"
 #include "base/compiler_specific.h"
 #include "base/logging.h"
 #include "base/message_loop/message_loop.h"
 #include "ppapi/c/pp_completion_callback.h"
 #include "ppapi/shared_impl/proxy_lock.h"
 #include "ppapi/shared_impl/tracked_callback.h"
 
 namespace ppapi {
 
 // CallbackTracker -------------------------------------------------------------
 
-CallbackTracker::CallbackTracker() : abort_all_called_(false) {
-}
+CallbackTracker::CallbackTracker() : abort_all_called_(false) {}
 
 void CallbackTracker::AbortAll() {
   // Iterate over a copy:
   // 1) because |Abort()| calls |Remove()| (indirectly).
   // 2) So we can drop the lock before calling in to TrackedCallback.
   CallbackSetMap pending_callbacks_copy;
   {
     base::AutoLock acquire(lock_);
     pending_callbacks_copy = pending_callbacks_;
     abort_all_called_ = true;
@@ skipping 54 matching lines @@
   CallbackSet::iterator it = map_it->second.find(tracked_callback);
   DCHECK(it != map_it->second.end());
   map_it->second.erase(it);
 
   // If there are no pending callbacks left for this ID, get rid of the entry.
   if (map_it->second.empty())
     pending_callbacks_.erase(map_it);
 }
 
 }  // namespace ppapi