[BlobAsync] Disk support for blob storage

storage/browser/blob/blob_data_builder.h

Index: storage/browser/blob/blob_data_builder.h
diff --git a/storage/browser/blob/blob_data_builder.h b/storage/browser/blob/blob_data_builder.h
index f304f446555cff8fa0f9291fea32bb2a95b72051..9ccbc21b498948dc1893dd3e0aa53a65a265e9cf 100644
--- a/storage/browser/blob/blob_data_builder.h
+++ b/storage/browser/blob/blob_data_builder.h
@@ -16,6 +16,7 @@
 #include "base/memory/ref_counted.h"
 #include "storage/browser/blob/blob_data_item.h"
 #include "storage/browser/blob/blob_data_snapshot.h"
+#include "storage/browser/blob/shareable_file_reference.h"
 #include "storage/browser/storage_browser_export.h"
 
 namespace disk_cache {
@@ -26,6 +27,8 @@ namespace storage {
 class BlobStorageContext;
 class ShareableFileReference;
 
+// A builder should only be used once to create a blob. Use
+// BlobDataHandle::GetBlobStatus to check for an error after creating the blob.
 class STORAGE_EXPORT BlobDataBuilder {
  public:
   using DataHandle = BlobDataItem::DataHandle;
@@ -106,6 +109,7 @@ class STORAGE_EXPORT BlobDataBuilder {
   void AppendDiskCacheEntry(const scoped_refptr<DataHandle>& data_handle,
                             disk_cache::Entry* disk_cache_entry,
                             int disk_cache_stream_index);
+
   // The content of the side data is accessible with BlobReader::ReadSideData().
   void AppendDiskCacheEntryWithSideData(
       const scoped_refptr<DataHandle>& data_handle,
@@ -124,8 +128,10 @@ class STORAGE_EXPORT BlobDataBuilder {
   void Clear();
 
  private:
-  friend class BlobStorageContext;
   friend class BlobAsyncBuilderHostTest;
+  friend struct BlobFlattener;
+  friend class BlobStorageContext;
+  FRIEND_TEST_ALL_PREFIXES(BlobStorageContextTest, BuildBlobFuzzish);
   friend bool operator==(const BlobDataBuilder& a, const BlobDataBuilder& b);
   friend bool operator==(const BlobDataSnapshot& a, const BlobDataBuilder& b);
   friend STORAGE_EXPORT void PrintTo(const BlobDataBuilder& x,