IndexedDB: Test that Blink ack's blobs upon receipt.

storage/browser/blob/blob_storage_context.h

 // Copyright (c) 2013 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.
 
 #ifndef STORAGE_BROWSER_BLOB_BLOB_STORAGE_CONTEXT_H_
 #define STORAGE_BROWSER_BLOB_BLOB_STORAGE_CONTEXT_H_
 
 #include <map>
 #include <string>
 #include <vector>
@@ skipping 44 matching lines @@
   // To cleanly use a builder multiple times, please call Clone() on the
   // builder, or even better for memory savings, clear the builder and append
   // the previously constructed blob.
   scoped_ptr<BlobDataHandle> AddFinishedBlob(BlobDataBuilder* builder);
 
   // Useful for coining blob urls from within the browser process.
   bool RegisterPublicBlobURL(const GURL& url, const std::string& uuid);
   void RevokePublicBlobURL(const GURL& url);
 
   size_t memory_usage() const { return memory_usage_; }
+  size_t blob_count() const { return blob_map_.size(); }
 
  private:
   friend class content::BlobStorageHost;
   friend class BlobDataHandle::BlobDataHandleShared;
   friend class ViewBlobInternalsJob;
 
   enum EntryFlags {
     EXCEEDED_MEMORY = 1 << 1,
   };
 
@@ skipping 61 matching lines @@
   // we count only the items of TYPE_DATA which are held in memory and not
   // items of TYPE_FILE.
   size_t memory_usage_;
 
   DISALLOW_COPY_AND_ASSIGN(BlobStorageContext);
 };
 
 }  // namespace storage
 
 #endif  // STORAGE_BROWSER_BLOB_BLOB_STORAGE_CONTEXT_H_