Add a size estimation mechanism to StoragePartitionHttpCacheDataRemover.

net/base/upload_disk_cache_entry_element_reader_unittest.cc

Index: net/base/upload_disk_cache_entry_element_reader_unittest.cc
diff --git a/net/base/upload_disk_cache_entry_element_reader_unittest.cc b/net/base/upload_disk_cache_entry_element_reader_unittest.cc
index 7321acc9cd5b54bc544cc984c4b0cc4a734988b9..1ca0c8a58d72a9b49917354d3a77a1d7b927a7e3 100644
--- a/net/base/upload_disk_cache_entry_element_reader_unittest.cc
+++ b/net/base/upload_disk_cache_entry_element_reader_unittest.cc
@@ -70,6 +70,10 @@ class DelayedReadEntry : public disk_cache::Entry {
     return entry_->GetDataSize(index);
   }
 
+  int GetEntrySize() const override {
+    return entry_->GetEntrySize();
+  }
+
   int ReadData(int index,
                int offset,
                IOBuffer* buf,