Wrap large IndexedDB values into Blobs before writing to LevelDB.

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

Index: third_party/WebKit/Source/modules/indexeddb/IDBTransaction.cpp
diff --git a/third_party/WebKit/Source/modules/indexeddb/IDBTransaction.cpp b/third_party/WebKit/Source/modules/indexeddb/IDBTransaction.cpp
index 2cd04cee1f4d08913dcd6c95af7bf885dcdffb1f..280d2d9fc2f6315b0fb8083707c714dfdd9dd8ec 100644
--- a/third_party/WebKit/Source/modules/indexeddb/IDBTransaction.cpp
+++ b/third_party/WebKit/Source/modules/indexeddb/IDBTransaction.cpp
@@ -36,6 +36,7 @@
 #include "modules/indexeddb/IDBIndex.h"
 #include "modules/indexeddb/IDBObjectStore.h"
 #include "modules/indexeddb/IDBOpenDBRequest.h"
+#include "modules/indexeddb/IDBRequestQueueItem.h"
 #include "modules/indexeddb/IDBTracing.h"
 #include "platform/bindings/ScriptState.h"
 #include "platform/bindings/V8PerIsolateData.h"
@@ -380,10 +381,40 @@ void IDBTransaction::RegisterRequest(IDBRequest* request) {
 
 void IDBTransaction::UnregisterRequest(IDBRequest* request) {
   DCHECK(request);
+
+  // TODO(pwnall): Finish figuring out the abort path.
+  // DCHECK_EQ(request->QueueItem(), nullptr);
+  IDBRequestQueueItem* queue_item = request->QueueItem();
+  if (queue_item) {
+    queue_item->CancelLoading();
+  }
+
   // If we aborted the request, it will already have been removed.
   request_list_.erase(request);
 }
 
+void IDBTransaction::EnqueueResult(
+    std::unique_ptr<IDBRequestQueueItem> result) {
+  DCHECK(result);
+  DCHECK(HasQueuedResults() || !result->IsReady());
+
+  result_queue_.push_back(std::move(result));
+  // StartLoading() may complete post-processing synchronously, so the result
+  // needs to be in the queue before StartLoading() is called.
+  result_queue_.back()->StartLoading();
+}
+
+void IDBTransaction::OnResultReady() {

[dmurph, 2017/05/23 18:16:39]

Can you rename this to SendPendingReadyResponses()? Or something else that
described this a little more directly?

[pwnall, 2017/05/25 13:27:11]

Let's figure out a good name in the next pass.

+  while (!result_queue_.empty()) {
+    IDBRequestQueueItem* result = result_queue_.front().get();
+    if (!result->IsReady())
+      break;
+
+    result->EnqueueResponse();

[dmurph, 2017/05/23 18:16:39]

If you change to callbacks.... you can make this just grab the callback and run
it (so less logic methods on that item). Or, make it something like
TakeEnqueueResponseCallback(), where the transaction owns it and that guarentees
it can't be called twice (trying to replicate your constraints with the
dchecks).

[pwnall, 2017/05/25 13:27:12]

Per in person discussion, I've introduced a WTF::Closure to decouple
IDBRequestQueueItem from IDBTransaction.

+    result_queue_.pop_front();
+  }
+}
+
 void IDBTransaction::OnAbort(DOMException* error) {
   IDB_TRACE("IDBTransaction::onAbort");
   if (!GetExecutionContext()) {