Add a size estimation mechanism to StoragePartitionHttpCacheDataRemover.

net/disk_cache/memory/mem_entry_impl.cc

Index: net/disk_cache/memory/mem_entry_impl.cc
diff --git a/net/disk_cache/memory/mem_entry_impl.cc b/net/disk_cache/memory/mem_entry_impl.cc
index daa3980144ca569b2e8ef5946f5e1071d665d13d..e638263bee809908ffd7df825d2aa9376685089e 100644
--- a/net/disk_cache/memory/mem_entry_impl.cc
+++ b/net/disk_cache/memory/mem_entry_impl.cc
@@ -183,6 +183,13 @@ int32 MemEntryImpl::GetDataSize(int index) const {
   return data_size_[index];
 }
 
+int MemEntryImpl::GetEntrySize() const {
+  int result = 0;
+  for (int i = 0; i < NUM_STREAMS; ++i)
+    result += data_size_[i];
+  return result;
+}
+
 int MemEntryImpl::ReadData(int index, int offset, IOBuffer* buf, int buf_len,
                            const CompletionCallback& callback) {
   if (net_log_.IsCapturing()) {