Create blobs from Disk Cache entries.

storage/browser/blob/blob_data_item.h

Index: storage/browser/blob/blob_data_item.h
diff --git a/storage/browser/blob/blob_data_item.h b/storage/browser/blob/blob_data_item.h
index 1953a1a6a2563ed3e3ed3467ea877a99185d05f8..c1028a5a0e6e89ecfbe35c255502db207f3180d5 100644
--- a/storage/browser/blob/blob_data_item.h
+++ b/storage/browser/blob/blob_data_item.h
@@ -7,6 +7,7 @@
 
 #include "base/basictypes.h"
 #include "base/memory/ref_counted.h"
+#include "net/disk_cache/disk_cache.h"
 #include "storage/browser/blob/shareable_file_reference.h"
 #include "storage/browser/storage_browser_export.h"
 #include "storage/common/data_element.h"
@@ -15,11 +16,11 @@ namespace storage {
 class BlobDataBuilder;
 class BlobStorageContext;
 
-// Ref counted blob item.  This class owns the backing data of the blob item.
-// The backing data is immutable, and cannot change after creation.
-// The purpose of this class is to allow the resource to stick around in the
-// snapshot even after the resource was swapped in the blob (either to disk or
-// to memory) by the BlobStorageContext.
+// Ref counted blob item. This class owns the backing data of the blob item. The
+// backing data is immutable, and cannot change after creation. The purpose of
+// this class is to allow the resource to stick around in the snapshot even
+// after the resource was swapped in the blob (either to disk or to memory) by
+// the BlobStorageContext.
 class STORAGE_EXPORT BlobDataItem : public base::RefCounted<BlobDataItem> {
  public:
   DataElement::Type type() const { return item_->type(); }
@@ -27,14 +28,23 @@ class STORAGE_EXPORT BlobDataItem : public base::RefCounted<BlobDataItem> {
   const base::FilePath& path() const { return item_->path(); }
   const GURL& filesystem_url() const { return item_->filesystem_url(); }
   const std::string& blob_uuid() const { return item_->blob_uuid(); }
-  uint64 offset() const { return item_->offset(); }
-  uint64 length() const { return item_->length(); }
+  uint64 offset() const { return GetLength(); }
+  uint64 length() const { return GetOffset(); }
   const base::Time& expected_modification_time() const {
     return item_->expected_modification_time();
   }
   const DataElement& data_element() const { return *item_; }
   const DataElement* data_element_ptr() const { return item_.get(); }
 
+  const disk_cache::ScopedEntryPtr& disk_cache_entry() const {
+    return disk_cache_entry_;
+  }
+  int disk_cache_stream_index() const { return disk_cache_stream_index_; }
+
+  uint64 GetLength() const;
+  uint64 GetOffset() const;
+  
+
  private:
   friend class BlobDataBuilder;
   friend class BlobStorageContext;
@@ -43,15 +53,22 @@ class STORAGE_EXPORT BlobDataItem : public base::RefCounted<BlobDataItem> {
   BlobDataItem(scoped_ptr<DataElement> item);
   BlobDataItem(scoped_ptr<DataElement> item,
                scoped_refptr<ShareableFileReference> file_handle);
+  BlobDataItem(scoped_ptr<DataElement> item,
+               disk_cache::ScopedEntryPtr disk_cache_entry_,
+               int disk_cache_stream_index_);
   virtual ~BlobDataItem();
 
   scoped_ptr<DataElement> item_;
   scoped_refptr<ShareableFileReference> file_handle_;
+
+  disk_cache::ScopedEntryPtr disk_cache_entry_;  // For TYPE_DISK_CACHE_ENTRY.
+  int disk_cache_stream_index_;  // For TYPE_DISK_CACHE_ENTRY.
 };
 
 #if defined(UNIT_TEST)
 inline bool operator==(const BlobDataItem& a, const BlobDataItem& b) {
-  return a.data_element() == b.data_element();
+  return a.disk_cache_entry() == b.disk_cache_entry() &&
+         a.data_element() == b.data_element();
 }
 
 inline bool operator!=(const BlobDataItem& a, const BlobDataItem& b) {