Add a size estimation mechanism to StoragePartitionHttpCacheDataRemover.

net/disk_cache/simple/simple_entry_impl.cc

Index: net/disk_cache/simple/simple_entry_impl.cc
diff --git a/net/disk_cache/simple/simple_entry_impl.cc b/net/disk_cache/simple/simple_entry_impl.cc
index 391079276067eb4605be4dc29b6b72d0d401d6a3..2587f91aa0a2ef68d7ce1f465121f27d5917dc9b 100644
--- a/net/disk_cache/simple/simple_entry_impl.cc
+++ b/net/disk_cache/simple/simple_entry_impl.cc
@@ -339,6 +339,14 @@ int32 SimpleEntryImpl::GetDataSize(int stream_index) const {
   return data_size_[stream_index];
 }
 
+int SimpleEntryImpl::GetEntrySize() const {
+  DCHECK(io_thread_checker_.CalledOnValidThread());
+  int result = 0;
+  for (int i = 0; i < kSimpleEntryStreamCount; ++i)
+    result += GetDataSize(i);
+  return result;
+}
+
 int SimpleEntryImpl::ReadData(int stream_index,
                               int offset,
                               net::IOBuffer* buf,