Remove implicit conversions from scoped_refptr to T* in net/disk_cache/

net/disk_cache/blockfile/index_table_v3.cc

Index: net/disk_cache/blockfile/index_table_v3.cc
diff --git a/net/disk_cache/blockfile/index_table_v3.cc b/net/disk_cache/blockfile/index_table_v3.cc
index 999d5ac6cbd8cfc456e3d90cd5e09b1c0dbbbdcf..039cba7f0529e3844944e6c78d0f44dca8c69460 100644
--- a/net/disk_cache/blockfile/index_table_v3.cc
+++ b/net/disk_cache/blockfile/index_table_v3.cc
@@ -786,7 +786,7 @@ void IndexTable::OnBackupTimer() {
   memcpy(buffer->data(), header_, sizeof(*header_));
   memcpy(buffer->data() + sizeof(*header_), backup_bitmap_storage_.get(),
          num_words * 4);
-  backend_->SaveIndex(buffer, num_bytes);
+  backend_->SaveIndex(buffer.get(), num_bytes);
   modified_ = false;
 }