[IndexedDB] Refactoring to remove ref ptrs and host transaction ids.

content/browser/indexed_db/indexed_db_cursor.cc

Index: content/browser/indexed_db/indexed_db_cursor.cc
diff --git a/content/browser/indexed_db/indexed_db_cursor.cc b/content/browser/indexed_db/indexed_db_cursor.cc
index a029b08242f58b2e1acc888ce612f1f9e3760cda..f1713c56874c391c4b439f1ea4fb0ea9fb01b7ab 100644
--- a/content/browser/indexed_db/indexed_db_cursor.cc
+++ b/content/browser/indexed_db/indexed_db_cursor.cc
@@ -15,8 +15,15 @@
 #include "content/browser/indexed_db/indexed_db_tracing.h"
 #include "content/browser/indexed_db/indexed_db_transaction.h"
 #include "content/browser/indexed_db/indexed_db_value.h"
+#include "third_party/WebKit/public/platform/modules/indexeddb/WebIDBDatabaseException.h"
 
 namespace content {
+namespace {
+IndexedDBDatabaseError CreateTransactionAbortedError() {
+  return IndexedDBDatabaseError(blink::WebIDBDatabaseExceptionAbortError,
+                                "Transaction was aborted.");
+}
+}  // namespace
 
 IndexedDBCursor::IndexedDBCursor(
     std::unique_ptr<IndexedDBBackingStore::Cursor> cursor,
@@ -27,36 +34,52 @@ IndexedDBCursor::IndexedDBCursor(
       cursor_type_(cursor_type),
       transaction_(transaction),
       cursor_(std::move(cursor)),
-      closed_(false) {
-  transaction_->RegisterOpenCursor(this);
-}
+      closed_(false),
+      ptr_factory_(this) {}
 
-IndexedDBCursor::~IndexedDBCursor() {
-  transaction_->UnregisterOpenCursor(this);
-}
+IndexedDBCursor::~IndexedDBCursor() {}
 
 void IndexedDBCursor::Continue(std::unique_ptr<IndexedDBKey> key,
                                std::unique_ptr<IndexedDBKey> primary_key,
                                scoped_refptr<IndexedDBCallbacks> callbacks) {
   IDB_TRACE("IndexedDBCursor::Continue");
 
+  if (!transaction_) {
+    callbacks->OnError(CreateTransactionAbortedError());
+    return;
+  }
+
   transaction_->ScheduleTask(
-      task_type_,
-      base::Bind(&IndexedDBCursor::CursorIterationOperation,
-                 this,
-                 base::Passed(&key),
-                 base::Passed(&primary_key),
-                 callbacks));
+      task_type_, base::Bind(&IndexedDBCursor::CursorIterationOperation,
+                             ptr_factory_.GetWeakPtr(), base::Passed(&key),
+                             base::Passed(&primary_key), callbacks));
 }
 
 void IndexedDBCursor::Advance(uint32_t count,
                               scoped_refptr<IndexedDBCallbacks> callbacks) {
   IDB_TRACE("IndexedDBCursor::Advance");
 
+  if (!transaction_) {
+    callbacks->OnError(CreateTransactionAbortedError());
+    return;
+  }
+
   transaction_->ScheduleTask(
-      task_type_,
-      base::Bind(
-          &IndexedDBCursor::CursorAdvanceOperation, this, count, callbacks));
+      task_type_, base::Bind(&IndexedDBCursor::CursorAdvanceOperation,
+                             ptr_factory_.GetWeakPtr(), count, callbacks));
+}
+
+void IndexedDBCursor::Close() {
+  IDB_TRACE("IndexedDBCursor::Close");
+  closed_ = true;
+  cursor_.reset();
+  saved_cursor_.reset();
+  transaction_ = nullptr;
+}
+
+void IndexedDBCursor::RemoveCursorFromTransaction() {
+  if (transaction_)
+    transaction_->UnregisterOpenCursor(this);
 }
 
 void IndexedDBCursor::CursorAdvanceOperation(
@@ -104,12 +127,15 @@ void IndexedDBCursor::PrefetchContinue(
     scoped_refptr<IndexedDBCallbacks> callbacks) {
   IDB_TRACE("IndexedDBCursor::PrefetchContinue");
 
+  if (!transaction_) {
+    callbacks->OnError(CreateTransactionAbortedError());
+    return;
+  }
+
   transaction_->ScheduleTask(
       task_type_,
       base::Bind(&IndexedDBCursor::CursorPrefetchIterationOperation,
-                 this,
-                 number_to_fetch,
-                 callbacks));
+                 ptr_factory_.GetWeakPtr(), number_to_fetch, callbacks));
 }
 
 void IndexedDBCursor::CursorPrefetchIterationOperation(
@@ -197,11 +223,4 @@ leveldb::Status IndexedDBCursor::PrefetchReset(int used_prefetches,
   return s;
 }
 
-void IndexedDBCursor::Close() {
-  IDB_TRACE("IndexedDBCursor::Close");
-  closed_ = true;
-  cursor_.reset();
-  saved_cursor_.reset();
-}
-
 }  // namespace content