[IndexedDB] Hold referenced to IDB::put blobs in the IDBRequest

third_party/WebKit/Source/modules/indexeddb/IDBObjectStore.cpp

Index: third_party/WebKit/Source/modules/indexeddb/IDBObjectStore.cpp
diff --git a/third_party/WebKit/Source/modules/indexeddb/IDBObjectStore.cpp b/third_party/WebKit/Source/modules/indexeddb/IDBObjectStore.cpp
index 2022121aacc4b027b5b200a749a67e4ef3c6f685..7d9eca215848c614b4b1e83b87e054fa63e91579 100644
--- a/third_party/WebKit/Source/modules/indexeddb/IDBObjectStore.cpp
+++ b/third_party/WebKit/Source/modules/indexeddb/IDBObjectStore.cpp
@@ -43,7 +43,9 @@
 #include "modules/indexeddb/IDBTracing.h"
 #include "platform/Histogram.h"
 #include "platform/SharedBuffer.h"
+#include "public/platform/Platform.h"
 #include "public/platform/WebBlobInfo.h"
+#include "public/platform/WebBlobRegistry.h"
 #include "public/platform/WebData.h"
 #include "public/platform/WebVector.h"
 #include "public/platform/modules/indexeddb/WebIDBKey.h"
@@ -506,6 +508,15 @@ IDBRequest* IDBObjectStore::put(ScriptState* script_state,
   serialized_value->ToWireBytes(wire_bytes);
   RefPtr<SharedBuffer> value_buffer = SharedBuffer::AdoptVector(wire_bytes);
 
+  // Add blob refs
+  blink::Platform* platform = blink::Platform::Current();
+  DCHECK(platform);
+  blink::WebBlobRegistry* registry = platform->GetBlobRegistry();
+  DCHECK(registry);
+  for (const WebBlobInfo& info : blob_info) {
+    registry->AddBlobDataRef(info.Uuid());

[michaeln, 2017/04/21 01:46:10]

Manual refcounting always makes me a little uneasy (are their any cases where
the balancing decref is not called and where is that balancing decref)

I think the serialized_value created on line 386 contains a map of
BlobDataHandles, so long as the handles in that map are retained the blobs will
not be deleted. Does the 'request' or 'callbacks' object outlive put()
completion? If so, maybe one of those could retain the references w/o manual
refcounting.

Also, is this change needed? At the time put() is called, there are valid refs
on any blobs in the value being put. Is there any chance the release msg of
those refs could beat the put msg sent on line 520? Maybe we can't depend on the
ordering of put vs release messages.

+  }
+
   BackendDB()->Put(transaction_->Id(), Id(), WebData(value_buffer), blob_info,
                    key, static_cast<WebIDBPutMode>(put_mode),
                    request->CreateWebCallbacks().release(), index_ids,