Add a size estimation mechanism to StoragePartitionHttpCacheDataRemover.

net/disk_cache/disk_cache.h

Index: net/disk_cache/disk_cache.h
diff --git a/net/disk_cache/disk_cache.h b/net/disk_cache/disk_cache.h
index 84c1ee99516654258486494a8afeacfb70ddc31d..089ef27a467b1d7eea2c29f34b2e8120557964bc 100644
--- a/net/disk_cache/disk_cache.h
+++ b/net/disk_cache/disk_cache.h
@@ -145,6 +145,17 @@ class NET_EXPORT Backend {
   virtual int DoomEntriesSince(base::Time initial_time,
                                const CompletionCallback& callback) = 0;
 
+  // Calculate the total size of entries satisfying the condition
+  // |initial_time| <= access_time < |end_time|. This supports unbounded
+  // counting in either direction by using null Time values for either argument.
+  // The return value is the number of bytes written or a net error code.

[rvargas (doing something else), 2015/09/12 00:13:02]

bytes written?

[msramek, 2015/09/15 11:42:36]

Done. Sorry, copy-paste.

+  // If this method returns ERR_IO_PENDING, the |callback| will be invoked when
+  // the operation completes.
+  virtual int CalculateSizeOfEntriesBetween(
+      base::Time initial_time,
+      base::Time end_time,
+      const CompletionCallback& callback) = 0;
+
   // Returns an iterator which will enumerate all entries of the cache in an
   // undefined order.
   virtual scoped_ptr<Iterator> CreateIterator() = 0;