Add a size estimation mechanism to StoragePartitionHttpCacheDataRemover.

net/disk_cache/disk_cache_test_base.h

Index: net/disk_cache/disk_cache_test_base.h
diff --git a/net/disk_cache/disk_cache_test_base.h b/net/disk_cache/disk_cache_test_base.h
index ef136f4429ffa75e2ac6ac3e66ba328d0955bef5..c6911a72870d12af0e51feb7856e992934b6e8ec 100644
--- a/net/disk_cache/disk_cache_test_base.h
+++ b/net/disk_cache/disk_cache_test_base.h
@@ -128,6 +128,7 @@ class DiskCacheTestWithCache : public DiskCacheTest {
   int DoomAllEntries();
   int DoomEntriesBetween(const base::Time initial_time,
                          const base::Time end_time);
+  int CalculateSizeOfAllEntries();
   int DoomEntriesSince(const base::Time initial_time);
   scoped_ptr<TestIterator> CreateIterator();
   void FlushQueueForTest();