Remove unused base::Closure instructions in disk_cache/simple/

Bug: 1007815
Change-Id: Ia37eefa5925208304469a2859f05a915d392525e
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2089828Reviewed-by: Maksim Orlovich <morlovich@chromium.org>
Commit-Queue: Anna Malova <amalova@chromium.org>
Cr-Commit-Position: refs/heads/master@{#747701}

net/disk_cache/simple/simple_backend_impl.cc

@@ -48,8 +48,6 @@
 #include "net/disk_cache/simple/simple_util.h"
 #include "net/disk_cache/simple/simple_version_upgrade.h"
 
-using base::Callback;
-using base::Closure;
 using base::FilePath;
 using base::Time;
 using base::DirectoryExists;

net/disk_cache/simple/simple_backend_impl.h

@@ -150,9 +150,6 @@ class NET_EXPORT_PRIVATE SimpleBackendImpl : public Backend,
 
   using EntryMap = std::unordered_map<uint64_t, SimpleEntryImpl*>;
 
-  using InitializeIndexCallback =
-      base::Callback<void(base::Time mtime, uint64_t max_size, int result)>;
-
   class ActiveEntryProxy;
   friend class ActiveEntryProxy;
 
@@ -276,9 +273,9 @@ class NET_EXPORT_PRIVATE SimpleBackendImpl : public Backend,
 
   // The set of all entries which are currently being doomed. To avoid races,
   // these entries cannot have Doom/Create/Open operations run until the doom
-  // is complete. The base::Closure |SimplePostDoomWaiter::run_post_doom| field
-  // is used to store deferred operations to be run at the completion of the
-  // Doom.
+  // is complete. The base::OnceClosure |SimplePostDoomWaiter::run_post_doom|
+  // field is used to store deferred operations to be run at the completion of
+  // the Doom.
   scoped_refptr<SimplePostDoomWaiterTable> post_doom_waiting_;
 
   net::NetLog* const net_log_;

net/disk_cache/simple/simple_entry_impl.cc

@@ -121,7 +121,6 @@ int PostToCallbackIfNeeded(bool sync_possible,
 
 }  // namespace
 
-using base::Closure;
 using base::OnceClosure;
 using base::FilePath;
 using base::Time;