Port messages sent by WebIDBFactoryImpl to Mojo.

content/browser/indexed_db/indexed_db_callbacks.cc

 // Copyright (c) 2012 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "content/browser/indexed_db/indexed_db_callbacks.h"
 
 #include <stddef.h>
 
 #include <algorithm>
 #include <utility>
 
 #include "base/metrics/histogram_macros.h"
 #include "base/strings/utf_string_conversions.h"
 #include "base/time/time.h"
 #include "content/browser/child_process_security_policy_impl.h"
 #include "content/browser/fileapi/fileapi_message_filter.h"
 #include "content/browser/indexed_db/indexed_db_blob_info.h"
 #include "content/browser/indexed_db/indexed_db_connection.h"
 #include "content/browser/indexed_db/indexed_db_context_impl.h"
 #include "content/browser/indexed_db/indexed_db_cursor.h"
-#include "content/browser/indexed_db/indexed_db_database_callbacks.h"
 #include "content/browser/indexed_db/indexed_db_database_error.h"
 #include "content/browser/indexed_db/indexed_db_metadata.h"
 #include "content/browser/indexed_db/indexed_db_return_value.h"
 #include "content/browser/indexed_db/indexed_db_tracing.h"
 #include "content/browser/indexed_db/indexed_db_value.h"
 #include "content/common/indexed_db/indexed_db_constants.h"
 #include "content/common/indexed_db/indexed_db_messages.h"
 #include "storage/browser/blob/blob_storage_context.h"
 #include "storage/browser/blob/shareable_file_reference.h"
 #include "storage/browser/quota/quota_manager.h"
 
+using indexed_db::mojom::CallbacksAssociatedPtrInfo;
 using storage::ShareableFileReference;
 
 namespace content {
 
 namespace {
+
 const int32_t kNoCursor = -1;
-const int32_t kNoDatabaseCallbacks = -1;
 const int64_t kNoTransaction = -1;
+
+::indexed_db::mojom::DatabaseMetadataPtr ConvertMetadata(
+    const content::IndexedDBDatabaseMetadata& web_metadata) {

[dcheng, 2016/10/05 08:00:03]

Is it possible to use typemapping for these conversions rather than embedding it
here? Documentation at
https://www.chromium.org/developers/design-documents/mojo/type-mapping, and I'm
happy to help as well.

(Similar comments apply to the other conversion helpers)

[Reilly Grant (use Gerrit), 2016/10/05 09:16:25]

This particular case is tricky because I need to map to
content::IndexedDBDatabaseMetadata in the browser process and
blink::WebIDBMetadata in the render process. I don't think I can do that with a
typemap because they're both using the same variant.

+  auto metadata = ::indexed_db::mojom::DatabaseMetadata::New();
+  metadata->id = web_metadata.id;
+  metadata->name = web_metadata.name;
+  metadata->version = web_metadata.version;
+  metadata->max_object_store_id = web_metadata.max_object_store_id;
+
+  for (const auto& iter : web_metadata.object_stores) {
+    const content::IndexedDBObjectStoreMetadata& web_store_metadata =
+        iter.second;
+    auto store_metadata = ::indexed_db::mojom::ObjectStoreMetadata::New();
+    store_metadata->id = web_store_metadata.id;
+    store_metadata->name = web_store_metadata.name;
+    store_metadata->key_path = web_store_metadata.key_path;
+    store_metadata->auto_increment = web_store_metadata.auto_increment;
+    store_metadata->max_index_id = web_store_metadata.max_index_id;
+
+    for (const auto& index_iter : web_store_metadata.indexes) {
+      const content::IndexedDBIndexMetadata& web_index_metadata =
+          index_iter.second;
+      auto index_metadata = ::indexed_db::mojom::IndexMetadata::New();
+      index_metadata->id = web_index_metadata.id;
+      index_metadata->name = web_index_metadata.name;
+      index_metadata->key_path = web_index_metadata.key_path;
+      index_metadata->unique = web_index_metadata.unique;
+      index_metadata->multi_entry = web_index_metadata.multi_entry;
+      store_metadata->indexes.push_back(std::move(index_metadata));
+    }
+    metadata->object_stores.push_back(std::move(store_metadata));
+  }
+  return metadata;
 }
+}
+
+class IndexedDBCallbacks::IOThreadHelper {
+ public:
+  IOThreadHelper(CallbacksAssociatedPtrInfo callbacks_info);
+  ~IOThreadHelper();
+
+  void SendBlocked(int64_t existing_version);
+  void SendError(const IndexedDBDatabaseError& error);
+  void SendSuccessDatabase(int32_t database_id,
+                           ::indexed_db::mojom::DatabaseMetadataPtr metadata);
+  void SendSuccessInteger(int64_t value);
+  void SendSuccessStringList(const std::vector<base::string16>& value);
+  void SendUpgradeNeeded(int32_t database_id,
+                         int64_t old_version,
+                         blink::WebIDBDataLoss data_loss,
+                         const std::string& data_loss_message,
+                         ::indexed_db::mojom::DatabaseMetadataPtr metadata);
+
+ private:
+  ::indexed_db::mojom::CallbacksAssociatedPtr callbacks_;
+};
 
 IndexedDBCallbacks::IndexedDBCallbacks(IndexedDBDispatcherHost* dispatcher_host,
                                        int32_t ipc_thread_id,
                                        int32_t ipc_callbacks_id)
     : dispatcher_host_(dispatcher_host),
       ipc_callbacks_id_(ipc_callbacks_id),
       ipc_thread_id_(ipc_thread_id),
       ipc_cursor_id_(kNoCursor),
       host_transaction_id_(kNoTransaction),
       ipc_database_id_(kNoDatabase),
-      ipc_database_callbacks_id_(kNoDatabaseCallbacks),
       data_loss_(blink::WebIDBDataLossNone),
-      sent_blocked_(false) {}
+      sent_blocked_(false),
+      helper_(nullptr) {}
 
 IndexedDBCallbacks::IndexedDBCallbacks(IndexedDBDispatcherHost* dispatcher_host,
                                        int32_t ipc_thread_id,
                                        int32_t ipc_callbacks_id,
                                        int32_t ipc_cursor_id)
     : dispatcher_host_(dispatcher_host),
       ipc_callbacks_id_(ipc_callbacks_id),
       ipc_thread_id_(ipc_thread_id),
       ipc_cursor_id_(ipc_cursor_id),
       host_transaction_id_(kNoTransaction),
       ipc_database_id_(kNoDatabase),
-      ipc_database_callbacks_id_(kNoDatabaseCallbacks),
       data_loss_(blink::WebIDBDataLossNone),
-      sent_blocked_(false) {}
+      sent_blocked_(false),
+      helper_(nullptr) {}
 
-IndexedDBCallbacks::IndexedDBCallbacks(IndexedDBDispatcherHost* dispatcher_host,
-                                       int32_t ipc_thread_id,
-                                       int32_t ipc_callbacks_id,
-                                       int32_t ipc_database_callbacks_id,
-                                       int64_t host_transaction_id,
-                                       const url::Origin& origin)
+IndexedDBCallbacks::IndexedDBCallbacks(
+    IndexedDBDispatcherHost* dispatcher_host,
+    const url::Origin& origin,
+    ::indexed_db::mojom::CallbacksAssociatedPtrInfo callbacks_info)
     : dispatcher_host_(dispatcher_host),
-      ipc_callbacks_id_(ipc_callbacks_id),
-      ipc_thread_id_(ipc_thread_id),
       ipc_cursor_id_(kNoCursor),
-      host_transaction_id_(host_transaction_id),
+      host_transaction_id_(kNoTransaction),
       origin_(origin),
       ipc_database_id_(kNoDatabase),
-      ipc_database_callbacks_id_(ipc_database_callbacks_id),
       data_loss_(blink::WebIDBDataLossNone),
-      sent_blocked_(false) {}
+      sent_blocked_(false),
+      helper_(nullptr) {
+  if (callbacks_info.is_valid())
+    helper_ = new IOThreadHelper(std::move(callbacks_info));
+}
 
-IndexedDBCallbacks::~IndexedDBCallbacks() {}
+IndexedDBCallbacks::~IndexedDBCallbacks() {
+  if (helper_)
+    BrowserThread::DeleteSoon(BrowserThread::IO, FROM_HERE, helper_);
+}
 
 void IndexedDBCallbacks::OnError(const IndexedDBDatabaseError& error) {
   DCHECK(dispatcher_host_.get());
 
-  dispatcher_host_->Send(new IndexedDBMsg_CallbacksError(
-      ipc_thread_id_, ipc_callbacks_id_, error.code(), error.message()));
+  if (helper_) {
+    BrowserThread::PostTask(BrowserThread::IO, FROM_HERE,
+                            base::Bind(&IOThreadHelper::SendError,
+                                       base::Unretained(helper_), error));
+  } else {
+    dispatcher_host_->Send(new IndexedDBMsg_CallbacksError(
+        ipc_thread_id_, ipc_callbacks_id_, error.code(), error.message()));
+  }
   dispatcher_host_ = NULL;
 
   if (!connection_open_start_time_.is_null()) {
     UMA_HISTOGRAM_MEDIUM_TIMES(
         "WebCore.IndexedDB.OpenTime.Error",
         base::TimeTicks::Now() - connection_open_start_time_);
     connection_open_start_time_ = base::TimeTicks();
   }
 }
 
 void IndexedDBCallbacks::OnSuccess(const std::vector<base::string16>& value) {
   DCHECK(dispatcher_host_.get());
-
+  DCHECK(helper_);
   DCHECK_EQ(kNoCursor, ipc_cursor_id_);
   DCHECK_EQ(kNoTransaction, host_transaction_id_);
   DCHECK_EQ(kNoDatabase, ipc_database_id_);
-  DCHECK_EQ(kNoDatabaseCallbacks, ipc_database_callbacks_id_);
-  DCHECK_EQ(blink::WebIDBDataLossNone, data_loss_);
 
-  std::vector<base::string16> list;
-  for (unsigned i = 0; i < value.size(); ++i)
-    list.push_back(value[i]);
-
-  dispatcher_host_->Send(new IndexedDBMsg_CallbacksSuccessStringList(
-      ipc_thread_id_, ipc_callbacks_id_, list));
+  BrowserThread::PostTask(BrowserThread::IO, FROM_HERE,
+                          base::Bind(&IOThreadHelper::SendSuccessStringList,
+                                     base::Unretained(helper_), value));
   dispatcher_host_ = NULL;
 }
 
 void IndexedDBCallbacks::OnBlocked(int64_t existing_version) {
   DCHECK(dispatcher_host_.get());
-
+  DCHECK(helper_);
   DCHECK_EQ(kNoCursor, ipc_cursor_id_);
-  // No transaction/db callbacks for DeleteDatabase.
-  DCHECK_EQ(kNoTransaction == host_transaction_id_,
-            kNoDatabaseCallbacks == ipc_database_callbacks_id_);
-  DCHECK_EQ(kNoDatabase, ipc_database_id_);
 
   if (sent_blocked_)
     return;
 
   sent_blocked_ = true;
-  dispatcher_host_->Send(new IndexedDBMsg_CallbacksIntBlocked(
-      ipc_thread_id_, ipc_callbacks_id_, existing_version));
+
+  BrowserThread::PostTask(
+      BrowserThread::IO, FROM_HERE,
+      base::Bind(&IOThreadHelper::SendBlocked, base::Unretained(helper_),
+                 existing_version));
 
   if (!connection_open_start_time_.is_null()) {
     UMA_HISTOGRAM_MEDIUM_TIMES(
         "WebCore.IndexedDB.OpenTime.Blocked",
         base::TimeTicks::Now() - connection_open_start_time_);
     connection_open_start_time_ = base::TimeTicks();
   }
 }
 
 void IndexedDBCallbacks::OnUpgradeNeeded(
     int64_t old_version,
     std::unique_ptr<IndexedDBConnection> connection,
     const IndexedDBDatabaseMetadata& metadata,
     const IndexedDBDataLossInfo& data_loss_info) {
   DCHECK(dispatcher_host_.get());
-
+  DCHECK(helper_);
+  DCHECK_NE(kNoTransaction, host_transaction_id_);
   DCHECK_EQ(kNoCursor, ipc_cursor_id_);
-  DCHECK_NE(kNoTransaction, host_transaction_id_);
   DCHECK_EQ(kNoDatabase, ipc_database_id_);
-  DCHECK_NE(kNoDatabaseCallbacks, ipc_database_callbacks_id_);
 
   data_loss_ = data_loss_info.status;
   dispatcher_host_->RegisterTransactionId(host_transaction_id_, origin_);
   int32_t ipc_database_id =
-      dispatcher_host_->Add(connection.release(), ipc_thread_id_, origin_);
+      dispatcher_host_->Add(connection.release(), origin_);
   if (ipc_database_id < 0)
     return;
+
   ipc_database_id_ = ipc_database_id;
-  IndexedDBMsg_CallbacksUpgradeNeeded_Params params;
-  params.ipc_thread_id = ipc_thread_id_;
-  params.ipc_callbacks_id = ipc_callbacks_id_;
-  params.ipc_database_id = ipc_database_id;
-  params.ipc_database_callbacks_id = ipc_database_callbacks_id_;
-  params.old_version = old_version;
-  params.idb_metadata = IndexedDBDispatcherHost::ConvertMetadata(metadata);
-  params.data_loss = data_loss_info.status;
-  params.data_loss_message = data_loss_info.message;
-  dispatcher_host_->Send(new IndexedDBMsg_CallbacksUpgradeNeeded(params));
+
+  BrowserThread::PostTask(
+      BrowserThread::IO, FROM_HERE,
+      base::Bind(&IOThreadHelper::SendUpgradeNeeded, base::Unretained(helper_),
+                 ipc_database_id, old_version, data_loss_info.status,
+                 data_loss_info.message,
+                 base::Passed(ConvertMetadata(metadata))));
 
   if (!connection_open_start_time_.is_null()) {
     UMA_HISTOGRAM_MEDIUM_TIMES(
         "WebCore.IndexedDB.OpenTime.UpgradeNeeded",
         base::TimeTicks::Now() - connection_open_start_time_);
     connection_open_start_time_ = base::TimeTicks();
   }
 }
 
 void IndexedDBCallbacks::OnSuccess(
     std::unique_ptr<IndexedDBConnection> connection,
     const IndexedDBDatabaseMetadata& metadata) {
   DCHECK(dispatcher_host_.get());
-
+  DCHECK(helper_);
   DCHECK_EQ(kNoCursor, ipc_cursor_id_);
   DCHECK_NE(kNoTransaction, host_transaction_id_);
   DCHECK_NE(ipc_database_id_ == kNoDatabase, !connection);
-  DCHECK_NE(kNoDatabaseCallbacks, ipc_database_callbacks_id_);
 
   scoped_refptr<IndexedDBCallbacks> self(this);
 
   int32_t ipc_object_id = kNoDatabase;
   // Only register if the connection was not previously sent in OnUpgradeNeeded.
   if (ipc_database_id_ == kNoDatabase) {
-    ipc_object_id =
-        dispatcher_host_->Add(connection.release(), ipc_thread_id_, origin_);
+    ipc_object_id = dispatcher_host_->Add(connection.release(), origin_);
   }
 
-  dispatcher_host_->Send(new IndexedDBMsg_CallbacksSuccessIDBDatabase(
-      ipc_thread_id_,
-      ipc_callbacks_id_,
-      ipc_database_callbacks_id_,
-      ipc_object_id,
-      IndexedDBDispatcherHost::ConvertMetadata(metadata)));
+  BrowserThread::PostTask(BrowserThread::IO, FROM_HERE,
+                          base::Bind(&IOThreadHelper::SendSuccessDatabase,
+                                     base::Unretained(helper_), ipc_object_id,
+                                     base::Passed(ConvertMetadata(metadata))));
   dispatcher_host_ = NULL;
 
   if (!connection_open_start_time_.is_null()) {
     UMA_HISTOGRAM_MEDIUM_TIMES(
         "WebCore.IndexedDB.OpenTime.Success",
         base::TimeTicks::Now() - connection_open_start_time_);
     connection_open_start_time_ = base::TimeTicks();
   }
 }
 
@@ skipping 109 matching lines @@
       iter.mark_used_callback().Run();
   }
   DCHECK(!BrowserThread::CurrentlyOn(BrowserThread::IO));
   BrowserThread::PostTask(BrowserThread::IO, FROM_HERE, callback);
 }
 
 void IndexedDBCallbacks::OnSuccess(scoped_refptr<IndexedDBCursor> cursor,
                                    const IndexedDBKey& key,
                                    const IndexedDBKey& primary_key,
                                    IndexedDBValue* value) {
+  DCHECK(!helper_);
   DCHECK(dispatcher_host_.get());
 
   DCHECK_EQ(kNoCursor, ipc_cursor_id_);
   DCHECK_EQ(kNoTransaction, host_transaction_id_);
   DCHECK_EQ(kNoDatabase, ipc_database_id_);
-  DCHECK_EQ(kNoDatabaseCallbacks, ipc_database_callbacks_id_);
   DCHECK_EQ(blink::WebIDBDataLossNone, data_loss_);
 
   int32_t ipc_object_id = dispatcher_host_->Add(cursor.get());
   std::unique_ptr<IndexedDBMsg_CallbacksSuccessIDBCursor_Params> params(
       new IndexedDBMsg_CallbacksSuccessIDBCursor_Params());
   params->ipc_thread_id = ipc_thread_id_;
   params->ipc_callbacks_id = ipc_callbacks_id_;
   params->ipc_cursor_id = ipc_object_id;
   params->key = key;
   params->primary_key = primary_key;
@@ skipping 13 matching lines @@
                                IndexedDBMsg_CallbacksSuccessIDBCursor>,
             base::Owned(params.release()), dispatcher_host_, value->blob_info,
             base::Unretained(&p->value.blob_or_file_info)));
   }
   dispatcher_host_ = NULL;
 }
 
 void IndexedDBCallbacks::OnSuccess(const IndexedDBKey& key,
                                    const IndexedDBKey& primary_key,
                                    IndexedDBValue* value) {
+  DCHECK(!helper_);
   DCHECK(dispatcher_host_.get());
 
   DCHECK_NE(kNoCursor, ipc_cursor_id_);
   DCHECK_EQ(kNoTransaction, host_transaction_id_);
   DCHECK_EQ(kNoDatabase, ipc_database_id_);
-  DCHECK_EQ(kNoDatabaseCallbacks, ipc_database_callbacks_id_);
   DCHECK_EQ(blink::WebIDBDataLossNone, data_loss_);
 
   IndexedDBCursor* idb_cursor =
       dispatcher_host_->GetCursorFromId(ipc_cursor_id_);
 
   DCHECK(idb_cursor);
   if (!idb_cursor)
     return;
 
   std::unique_ptr<IndexedDBMsg_CallbacksSuccessCursorContinue_Params> params(
@@ skipping 22 matching lines @@
                    value->blob_info,
                    base::Unretained(&p->value.blob_or_file_info)));
   }
   dispatcher_host_ = NULL;
 }
 
 void IndexedDBCallbacks::OnSuccessWithPrefetch(
     const std::vector<IndexedDBKey>& keys,
     const std::vector<IndexedDBKey>& primary_keys,
     std::vector<IndexedDBValue>* values) {
+  DCHECK(!helper_);
   DCHECK_EQ(keys.size(), primary_keys.size());
   DCHECK_EQ(keys.size(), values->size());
 
   DCHECK(dispatcher_host_.get());
 
   DCHECK_NE(kNoCursor, ipc_cursor_id_);
   DCHECK_EQ(kNoTransaction, host_transaction_id_);
   DCHECK_EQ(kNoDatabase, ipc_database_id_);
-  DCHECK_EQ(kNoDatabaseCallbacks, ipc_database_callbacks_id_);
   DCHECK_EQ(blink::WebIDBDataLossNone, data_loss_);
 
   std::vector<IndexedDBKey> msg_keys;
   std::vector<IndexedDBKey> msg_primary_keys;
 
   for (size_t i = 0; i < keys.size(); ++i) {
     msg_keys.push_back(keys[i]);
     msg_primary_keys.push_back(primary_keys[i]);
   }
 
@@ skipping 28 matching lines @@
                                        dispatcher_host_,
                                        *values));
   } else {
     dispatcher_host_->Send(
         new IndexedDBMsg_CallbacksSuccessCursorPrefetch(*params.get()));
   }
   dispatcher_host_ = NULL;
 }
 
 void IndexedDBCallbacks::OnSuccess(IndexedDBReturnValue* value) {
+  DCHECK(!helper_);
   DCHECK(dispatcher_host_.get());
 
   if (value && value->primary_key.IsValid()) {
     DCHECK_EQ(kNoCursor, ipc_cursor_id_);
   } else {
     DCHECK(kNoCursor == ipc_cursor_id_ || value == NULL);
   }
   DCHECK_EQ(kNoTransaction, host_transaction_id_);
   DCHECK_EQ(kNoDatabase, ipc_database_id_);
-  DCHECK_EQ(kNoDatabaseCallbacks, ipc_database_callbacks_id_);
   DCHECK_EQ(blink::WebIDBDataLossNone, data_loss_);
 
   std::unique_ptr<IndexedDBMsg_CallbacksSuccessValue_Params> params(
       new IndexedDBMsg_CallbacksSuccessValue_Params());
   params->ipc_thread_id = ipc_thread_id_;
   params->ipc_callbacks_id = ipc_callbacks_id_;
   if (value && value->primary_key.IsValid()) {
     params->value.primary_key = value->primary_key;
     params->value.key_path = value->key_path;
   }
@@ skipping 11 matching lines @@
                    base::Owned(params.release()), dispatcher_host_,
                    value->blob_info,
                    base::Unretained(&p->value.blob_or_file_info)));
   }
   dispatcher_host_ = NULL;
 }
 
 void IndexedDBCallbacks::OnSuccessArray(
     std::vector<IndexedDBReturnValue>* values,
     const IndexedDBKeyPath& key_path) {
+  DCHECK(!helper_);
   DCHECK(dispatcher_host_.get());
 
   DCHECK_EQ(kNoTransaction, host_transaction_id_);
   DCHECK_EQ(kNoDatabase, ipc_database_id_);
-  DCHECK_EQ(kNoDatabaseCallbacks, ipc_database_callbacks_id_);
   DCHECK_EQ(blink::WebIDBDataLossNone, data_loss_);
 
   std::unique_ptr<IndexedDBMsg_CallbacksSuccessArray_Params> params(
       new IndexedDBMsg_CallbacksSuccessArray_Params());
   params->ipc_thread_id = ipc_thread_id_;
   params->ipc_callbacks_id = ipc_callbacks_id_;
   params->values.resize(values->size());
 
   bool found_blob_info = false;
   for (size_t i = 0; i < values->size(); ++i) {
@@ skipping 18 matching lines @@
         base::Bind(BlobLookupForGetAll, base::Owned(params.release()),
                    dispatcher_host_, *values));
   } else {
     dispatcher_host_->Send(
         new IndexedDBMsg_CallbacksSuccessArray(*params.get()));
   }
   dispatcher_host_ = NULL;
 }
 
 void IndexedDBCallbacks::OnSuccess(const IndexedDBKey& value) {
+  DCHECK(!helper_);
   DCHECK(dispatcher_host_.get());
 
   DCHECK_EQ(kNoCursor, ipc_cursor_id_);
   DCHECK_EQ(kNoTransaction, host_transaction_id_);
   DCHECK_EQ(kNoDatabase, ipc_database_id_);
-  DCHECK_EQ(kNoDatabaseCallbacks, ipc_database_callbacks_id_);
   DCHECK_EQ(blink::WebIDBDataLossNone, data_loss_);
 
   dispatcher_host_->Send(new IndexedDBMsg_CallbacksSuccessIndexedDBKey(
       ipc_thread_id_, ipc_callbacks_id_, value));
   dispatcher_host_ = NULL;
 }
 
 void IndexedDBCallbacks::OnSuccess(int64_t value) {
   DCHECK(dispatcher_host_.get());
+  if (helper_) {
+    BrowserThread::PostTask(BrowserThread::IO, FROM_HERE,
+                            base::Bind(&IOThreadHelper::SendSuccessInteger,
+                                       base::Unretained(helper_), value));
+  } else {
+    DCHECK_EQ(kNoCursor, ipc_cursor_id_);
+    DCHECK_EQ(kNoTransaction, host_transaction_id_);
+    DCHECK_EQ(kNoDatabase, ipc_database_id_);
+    DCHECK_EQ(blink::WebIDBDataLossNone, data_loss_);
+
+    dispatcher_host_->Send(new IndexedDBMsg_CallbacksSuccessInteger(
+        ipc_thread_id_, ipc_callbacks_id_, value));
+  }
+  dispatcher_host_ = NULL;
+}
+
+void IndexedDBCallbacks::OnSuccess() {
+  DCHECK(!helper_);
+  DCHECK(dispatcher_host_.get());
 
   DCHECK_EQ(kNoCursor, ipc_cursor_id_);
   DCHECK_EQ(kNoTransaction, host_transaction_id_);
   DCHECK_EQ(kNoDatabase, ipc_database_id_);
-  DCHECK_EQ(kNoDatabaseCallbacks, ipc_database_callbacks_id_);
-  DCHECK_EQ(blink::WebIDBDataLossNone, data_loss_);
-
-  dispatcher_host_->Send(new IndexedDBMsg_CallbacksSuccessInteger(
-      ipc_thread_id_, ipc_callbacks_id_, value));
-  dispatcher_host_ = NULL;
-}
-
-void IndexedDBCallbacks::OnSuccess() {
-  DCHECK(dispatcher_host_.get());
-
-  DCHECK_EQ(kNoCursor, ipc_cursor_id_);
-  DCHECK_EQ(kNoTransaction, host_transaction_id_);
-  DCHECK_EQ(kNoDatabase, ipc_database_id_);
-  DCHECK_EQ(kNoDatabaseCallbacks, ipc_database_callbacks_id_);
   DCHECK_EQ(blink::WebIDBDataLossNone, data_loss_);
 
   dispatcher_host_->Send(new IndexedDBMsg_CallbacksSuccessUndefined(
       ipc_thread_id_, ipc_callbacks_id_));
   dispatcher_host_ = NULL;
 }
 
 void IndexedDBCallbacks::SetConnectionOpenStartTime(
     const base::TimeTicks& start_time) {
   connection_open_start_time_ = start_time;
 }
 
+IndexedDBCallbacks::IOThreadHelper::IOThreadHelper(
+    CallbacksAssociatedPtrInfo callbacks_info) {
+  callbacks_.Bind(std::move(callbacks_info));
+}
+
+IndexedDBCallbacks::IOThreadHelper::~IOThreadHelper() {}
+
+void IndexedDBCallbacks::IOThreadHelper::SendBlocked(int64_t existing_version) {
+  callbacks_->Blocked(existing_version);
+}
+
+void IndexedDBCallbacks::IOThreadHelper::SendError(
+    const IndexedDBDatabaseError& error) {
+  callbacks_->Error(error.code(), error.message());
+}
+
+void IndexedDBCallbacks::IOThreadHelper::SendSuccessDatabase(
+    int32_t database_id,
+    ::indexed_db::mojom::DatabaseMetadataPtr metadata) {
+  callbacks_->SuccessDatabase(database_id, std::move(metadata));
+}
+
+void IndexedDBCallbacks::IOThreadHelper::SendSuccessInteger(int64_t value) {
+  callbacks_->SuccessInteger(value);
+}
+
+void IndexedDBCallbacks::IOThreadHelper::SendSuccessStringList(
+    const std::vector<base::string16>& value) {
+  callbacks_->SuccessStringList(value);
+}
+
+void IndexedDBCallbacks::IOThreadHelper::SendUpgradeNeeded(
+    int32_t database_id,
+    int64_t old_version,
+    blink::WebIDBDataLoss data_loss,
+    const std::string& data_loss_message,
+    ::indexed_db::mojom::DatabaseMetadataPtr metadata) {
+  callbacks_->UpgradeNeeded(
+      database_id, old_version,
+      static_cast<::indexed_db::mojom::DataLoss>(data_loss), data_loss_message,

[dcheng, 2016/10/05 08:00:03]

Similar to above, would it be possible to use EnumTraits here?

[Reilly Grant (use Gerrit), 2016/10/05 09:16:25]

Done. Wasn't sure this worked for enums. Glad it does.

+      std::move(metadata));
+}
+
 }  // namespace content