[BlobAsync] Disk support for blob storage

content/browser/blob_storage/chrome_blob_storage_context.h

Index: content/browser/blob_storage/chrome_blob_storage_context.h
diff --git a/content/browser/blob_storage/chrome_blob_storage_context.h b/content/browser/blob_storage/chrome_blob_storage_context.h
index bd02cb1e2d8e9d6b9b120ce90833e101ecb1e21a..a255fe3ce8993e9c4ee4f668713d458f5ac6f52c 100644
--- a/content/browser/blob_storage/chrome_blob_storage_context.h
+++ b/content/browser/blob_storage/chrome_blob_storage_context.h
@@ -10,6 +10,7 @@
 
 #include <memory>
 
+#include "base/files/file_path.h"
 #include "base/memory/ref_counted.h"
 #include "base/sequenced_task_runner_helpers.h"
 #include "content/common/content_export.h"
@@ -70,6 +71,11 @@ class CONTENT_EXPORT ChromeBlobStorageContext
 
   void DeleteOnCorrectThread() const;
 
+  // Called after successfully creating our blob directory. This enables disk
+  // usage on |context_|.
+  void OnBlobDirectoryCreated(const base::FilePath& blob_storage_directory);
+
+  base::FilePath blob_storage_dir_;
   std::unique_ptr<storage::BlobStorageContext> context_;
 };