[BlobStorage] BlobMemoryController & tests

storage/browser/blob/internal_blob_data.cc

 // Copyright 2015 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 "storage/browser/blob/internal_blob_data.h"
 
 #include <stddef.h>
 
 #include <memory>
 #include <utility>
@@ skipping 40 matching lines @@
 }
 
 const std::vector<scoped_refptr<ShareableBlobDataItem>>&
 InternalBlobData::items() const {
   return items_;
 }
 
 void InternalBlobData::RemoveBlobFromShareableItems(
     const std::string& blob_uuid) {
   for (auto& data_item : items_) {
-    data_item->referencing_blobs().erase(blob_uuid);
+    data_item->referencing_blobs_mutable()->erase(blob_uuid);

[michaeln, 2016/10/11 20:55:24]

Would it be less error prone to "maybe free" each item when its collection of
referencing blobs becomes empty?

[dmurph, 2016/10/13 00:39:31]

Yeah. Done.

   }
 }
 
 size_t InternalBlobData::GetUnsharedMemoryUsage() const {
   size_t memory = 0;
   base::hash_set<void*> seen_items;
   for (const auto& data_item : items_) {
     if (data_item->item()->type() != DataElement::TYPE_BYTES ||
         data_item->referencing_blobs().size() > 1 ||
         seen_items.find(data_item.get()) != seen_items.end()) {
@@ skipping 16 matching lines @@
       if (data_item->referencing_blobs().size() == 1 &&
           seen_items.find(data_item.get()) == seen_items.end()) {
         *unshared_memory += data_item->item()->length();
         seen_items.insert(data_item.get());
       }
     }
   }
 }
 
 }  // namespace storage