Add a size estimation mechanism to StoragePartitionHttpCacheDataRemover.

net/http/mock_http_cache.h

Index: net/http/mock_http_cache.h
diff --git a/net/http/mock_http_cache.h b/net/http/mock_http_cache.h
index 632bb3e63c16996290e5ed945c6d7f7909eea5c0..42e246ca3f1f6fa3c5a7f0ec8b3c2ab4e8b7a77a 100644
--- a/net/http/mock_http_cache.h
+++ b/net/http/mock_http_cache.h
@@ -127,6 +127,10 @@ class MockDiskCache : public disk_cache::Backend {
                          const CompletionCallback& callback) override;
   int DoomEntriesSince(base::Time initial_time,
                        const CompletionCallback& callback) override;
+  int CalculateSizeOfEntriesBetween(
+      base::Time initial_time,
+      base::Time end_time,
+      const CompletionCallback& callback) override;
   scoped_ptr<Iterator> CreateIterator() override;
   void GetStats(base::StringPairs* stats) override;
   void OnExternalCacheHit(const std::string& key) override;