Create blobs from Disk Cache entries.

storage/browser/blob/blob_data_item.cc

Index: storage/browser/blob/blob_data_item.cc
diff --git a/storage/browser/blob/blob_data_item.cc b/storage/browser/blob/blob_data_item.cc
index 504a1c3e8be39939d58c0ac19702f7c6d3e2ac89..22ed7bb7dfcc885584f86b0e583a3077d81405c0 100644
--- a/storage/browser/blob/blob_data_item.cc
+++ b/storage/browser/blob/blob_data_item.cc
@@ -6,12 +6,38 @@
 
 namespace storage {
 
-BlobDataItem::BlobDataItem(scoped_ptr<DataElement> item,
-                           scoped_refptr<ShareableFileReference> file_handle)
-    : item_(item.Pass()), file_handle_(file_handle) {
+uint64 BlobDataItem::GetLength() const {
+  if (type() == DataElement::TYPE_DISK_CACHE_ENTRY)
+    return disk_cache_entry_->GetDataSize(disk_cache_stream_index_);
+  return item_->length();
+}
+
+uint64 BlobDataItem::GetOffset() const {
+  if (type() == DataElement::TYPE_DISK_CACHE_ENTRY)
+    return 0;
+  return item_->offset();
 }
+
 BlobDataItem::BlobDataItem(scoped_ptr<DataElement> item) : item_(item.Pass()) {
 }
+
+BlobDataItem::BlobDataItem(
+    scoped_ptr<DataElement> item,
+    const scoped_refptr<ShareableFileReference>& file_handle)
+    : item_(item.Pass()),
+      file_handle_(file_handle) {
+}
+
+BlobDataItem::BlobDataItem(scoped_ptr<DataElement> item,
+                           scoped_ptr<ExtraData> extra_data,
+                           disk_cache::ScopedEntryPtr disk_cache_entry,
+                           int disk_cache_stream_index)
+    : item_(item.Pass()),
+      extra_data_(extra_data.Pass()),
+      disk_cache_entry_(disk_cache_entry.Pass()),
+      disk_cache_stream_index_(disk_cache_stream_index) {
+}
+
 BlobDataItem::~BlobDataItem() {
 }