Add a size estimation mechanism to StoragePartitionHttpCacheDataRemover.

net/disk_cache/blockfile/entry_impl_v3.cc

Index: net/disk_cache/blockfile/entry_impl_v3.cc
diff --git a/net/disk_cache/blockfile/entry_impl_v3.cc b/net/disk_cache/blockfile/entry_impl_v3.cc
index 73719364829fb761998f0f765ebc86c9e0081be5..255261929313bc1184feb30c47861d15f9941e21 100644
--- a/net/disk_cache/blockfile/entry_impl_v3.cc
+++ b/net/disk_cache/blockfile/entry_impl_v3.cc
@@ -521,6 +521,13 @@ int32 EntryImplV3::GetDataSize(int index) const {
   return entry->Data()->data_size[index];
 }
 
+int EntryImplV3::GetEntrySize() const {
+  int result = 0;
+  for (int i = 0; i < kNumStreams; ++i)
+    result += GetDataSize(i);
+  return result;
+}
+
 int EntryImplV3::ReadData(int index, int offset, IOBuffer* buf, int buf_len,
                           const CompletionCallback& callback) {
   if (callback.is_null())