[FileSystem] Get rid of no longer needed snapshot blob.

Since all this runs on the same thread these days, there is no longer any
reason for FileSystemDispatcher::DidCreateSnapshotFile to create a
BlobDataHandle. The callbacks called by it already do the same
synchronously anyway.

Bug: none
Change-Id: I86cbc0f0c4feeb20b6495f6741493d9a11ec98b7
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/1975088Reviewed-by: Daniel Murphy <dmurph@chromium.org>
Commit-Queue: Marijn Kruisselbrink <mek@chromium.org>
Cr-Commit-Position: refs/heads/master@{#726446}

third_party/blink/renderer/modules/filesystem/dom_file_system_sync.cc

@@ -109,15 +109,7 @@ class CreateFileHelper final : public SnapshotFileCallbackBase {
 
   ~CreateFileHelper() override = default;
 
-  void DidCreateSnapshotFile(const FileMetadata& metadata,
-                             scoped_refptr<BlobDataHandle> snapshot) override {
-    // We can't directly use the snapshot blob data handle because the content
-    // type on it hasn't been set.  The |snapshot| param is here to provide a a
-    // chain of custody thru thread bridging that is held onto until *after*
-    // we've coined a File with a new handle that has the correct type set on
-    // it. This allows the blob storage system to track when a temp file can and
-    // can't be safely deleted.
-
+  void DidCreateSnapshotFile(const FileMetadata& metadata) override {
     result_->file_ =
         DOMFileSystemBase::CreateFile(metadata, url_, type_, name_);
   }

third_party/blink/renderer/modules/filesystem/file_system_callbacks.cc

@@ -290,18 +290,10 @@ SnapshotFileCallback::SnapshotFileCallback(DOMFileSystemBase* filesystem,
       success_callback_(std::move(success_callback)),
       error_callback_(std::move(error_callback)) {}
 
-void SnapshotFileCallback::DidCreateSnapshotFile(
-    const FileMetadata& metadata,
-    scoped_refptr<BlobDataHandle> snapshot) {
+void SnapshotFileCallback::DidCreateSnapshotFile(const FileMetadata& metadata) {
   if (!success_callback_)
     return;
 
-  // We can't directly use the snapshot blob data handle because the content
-  // type on it hasn't been set.  The |snapshot| param is here to provide a
-  // chain of custody thru thread bridging that is held onto until *after* we've
-  // coined a File with a new handle that has the correct type set on it. This
-  // allows the blob storage system to track when a temp file can and can't be
-  // safely deleted.
   std::move(success_callback_)
       .Run(DOMFileSystemBase::CreateFile(metadata, url_,
                                          file_system_->GetType(), name_));

third_party/blink/renderer/modules/filesystem/file_system_callbacks.h

@@ -80,9 +80,7 @@ class SnapshotFileCallbackBase {
   virtual ~SnapshotFileCallbackBase() = default;
 
   // Called when a snapshot file is created successfully.
-  virtual void DidCreateSnapshotFile(
-      const FileMetadata&,
-      scoped_refptr<BlobDataHandle> snapshot) = 0;
+  virtual void DidCreateSnapshotFile(const FileMetadata&) = 0;
 
   virtual void DidFail(base::File::Error error) = 0;
 };
@@ -245,8 +243,7 @@ class SnapshotFileCallback final : public SnapshotFileCallbackBase,
                        ExecutionContext*);
 
   // Called when a snapshot file is created successfully.
-  void DidCreateSnapshotFile(const FileMetadata&,
-                             scoped_refptr<BlobDataHandle> snapshot) override;
+  void DidCreateSnapshotFile(const FileMetadata&) override;
 
   // Called when a request operation has failed.
   void DidFail(base::File::Error error) override;

third_party/blink/renderer/modules/filesystem/file_system_dispatcher.cc

@@ -573,13 +573,7 @@ void FileSystemDispatcher::DidCreateSnapshotFile(
     FileMetadata file_metadata = FileMetadata::From(file_info);
     file_metadata.platform_path = FilePathToWebString(platform_path);
 
-    auto blob_data = std::make_unique<BlobData>();
-    blob_data->AppendFile(file_metadata.platform_path, 0, file_metadata.length,
-                          base::nullopt);
-    scoped_refptr<BlobDataHandle> snapshot_blob =
-        BlobDataHandle::Create(std::move(blob_data), file_metadata.length);
-
-    callbacks->DidCreateSnapshotFile(file_metadata, snapshot_blob);
+    callbacks->DidCreateSnapshotFile(file_metadata);
 
     if (listener) {
       mojo::Remote<mojom::blink::ReceivedSnapshotListener>(std::move(listener))