[Storage] Added blob items count histogram

storage/browser/blob/blob_storage_context.cc

 // 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.
 
 #include "storage/browser/blob/blob_storage_context.h"
 
 #include "base/bind.h"
 #include "base/location.h"
 #include "base/logging.h"
 #include "base/message_loop/message_loop_proxy.h"
@@ skipping 184 matching lines @@
 }
 
 void BlobStorageContext::FinishBuildingBlob(
     const std::string& uuid, const std::string& content_type) {
   DCHECK(IsBeingBuilt(uuid));
   BlobMap::iterator found = blob_map_.find(uuid);
   if (found == blob_map_.end())
     return;
   found->second.data->set_content_type(content_type);
   found->second.flags &= ~BEING_BUILT;
+  UMA_HISTOGRAM_COUNTS("Storage.Blob.ItemCount",
+                       found->second.data->items().size());
   UMA_HISTOGRAM_BOOLEAN(
       "Storage.Blob.ExceededMemory",
       (found->second.flags & EXCEEDED_MEMORY) == EXCEEDED_MEMORY);
 }
 
 void BlobStorageContext::CancelBuildingBlob(const std::string& uuid) {
   DCHECK(IsBeingBuilt(uuid));
   DecrementBlobRefCount(uuid);
 }
 
@@ skipping 108 matching lines @@
   if (found == blob_map_.end())
     return false;
   return found->second.flags & BEING_BUILT;
 }
 
 bool BlobStorageContext::IsUrlRegistered(const GURL& blob_url) {
   return public_blob_urls_.find(blob_url) != public_blob_urls_.end();
 }
 
 }  // namespace storage