Add a size estimation mechanism to StoragePartitionHttpCacheDataRemover.

net/disk_cache/blockfile/backend_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 "net/disk_cache/blockfile/backend_impl.h"
 
 #include "base/bind.h"
 #include "base/bind_helpers.h"
 #include "base/files/file.h"
 #include "base/files/file_path.h"
@@ skipping 392 matching lines @@
       next = NULL;
       SyncEndEnumeration(iterator.Pass());
     }
 
     node->Release();
   }
 
   return net::OK;
 }
 
+int BackendImpl::SyncCalculateSizeOfAllEntries() {
+  DCHECK_NE(net::APP_CACHE, cache_type_);
+  if (disabled_)
+    return net::ERR_FAILED;
+
+  return data_->header.num_bytes;
+}
+
 // We use OpenNextEntryImpl to retrieve elements from the cache, until we get
 // entries that are too old.
 int BackendImpl::SyncDoomEntriesSince(const base::Time initial_time) {
   DCHECK_NE(net::APP_CACHE, cache_type_);
   if (disabled_)
     return net::ERR_FAILED;
 
   stats_.OnEvent(Stats::DOOM_RECENT);
   for (;;) {
     scoped_ptr<Rankings::Iterator> iterator(new Rankings::Iterator());
@@ skipping 824 matching lines @@
   return net::ERR_IO_PENDING;
 }
 
 int BackendImpl::DoomEntriesSince(const base::Time initial_time,
                                   const CompletionCallback& callback) {
   DCHECK(!callback.is_null());
   background_queue_.DoomEntriesSince(initial_time, callback);
   return net::ERR_IO_PENDING;
 }
 
+int BackendImpl::CalculateSizeOfAllEntries(const CompletionCallback& callback) {
+  DCHECK(!callback.is_null());
+  background_queue_.CalculateSizeOfAllEntries(callback);
+  return net::ERR_IO_PENDING;
+}
+
 class BackendImpl::IteratorImpl : public Backend::Iterator {
  public:
   explicit IteratorImpl(base::WeakPtr<InFlightBackendIO> background_queue)
       : background_queue_(background_queue),
         iterator_(new Rankings::Iterator()) {
   }
 
   ~IteratorImpl() override {
     if (background_queue_)
       background_queue_->EndEnumeration(iterator_.Pass());
@@ skipping 824 matching lines @@
     if (total_memory > kMaxBuffersSize || total_memory <= 0)
       total_memory = kMaxBuffersSize;
 
     done = true;
   }
 
   return static_cast<int>(total_memory);
 }
 
 }  // namespace disk_cache