[IndexedDB] Adding sequence checkers in IndexedDBBackingStore

This change adds sequence checkers to all method calls in
* IndexedDBBackingStore
* IndexedDBBackingStore::Transaction
* IndexedDBBackingStore::Transaction::ChainedBlobWriterImpl
* LocalWriteClosure
* IndexedDBBackingStore::Cursor
* ObjectStoreKeyCursorImpl
* ObjectStoreCursorImpl
* IndexKeyCursorImpl
* IndexCursorImpl

R=enne@chromium.org

Bug: 1024966
Change-Id: I3c5912a73839a03ddb53aa058c694ec45d318cf7
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/1935028
Commit-Queue: Daniel Murphy <dmurph@chromium.org>
Reviewed-by: enne <enne@chromium.org>
Cr-Commit-Position: refs/heads/master@{#719336}

content/browser/indexed_db/indexed_db_backing_store.h

@@ -20,6 +20,7 @@
 #include "base/macros.h"
 #include "base/memory/ref_counted.h"
 #include "base/memory/weak_ptr.h"
+#include "base/sequence_checker.h"
 #include "base/strings/string_piece.h"
 #include "base/time/time.h"
 #include "base/timer/timer.h"
@@ -182,7 +183,7 @@ class CONTENT_EXPORT IndexedDBBackingStore {
 
     // This holds a BlobEntryKey and the encoded IndexedDBBlobInfo vector stored
     // under that key.
-    typedef std::vector<std::pair<BlobEntryKey, std::string> >
+    typedef std::vector<std::pair<BlobEntryKey, std::string>>
         BlobEntryKeyValuePairVec;
 
     class CONTENT_EXPORT WriteDescriptor {
@@ -271,6 +272,8 @@ class CONTENT_EXPORT IndexedDBBackingStore {
     void PartitionBlobsToRemove(BlobJournalType* dead_blobs,
                                 BlobJournalType* live_blobs) const;
 
+    SEQUENCE_CHECKER(idb_sequence_checker_);
+
     // This does NOT mean that this class can outlive the IndexedDBBackingStore.
     // This is only to protect against security issues before this class is
     // refactored away and this isn't necessary.
@@ -362,6 +365,8 @@ class CONTENT_EXPORT IndexedDBBackingStore {
     bool IsPastBounds() const;
     bool HaveEnteredRange() const;
 
+    SEQUENCE_CHECKER(idb_sequence_checker_);
+
     // This does NOT mean that this class can outlive the Transaction.
     // This is only to protect against security issues before this class is
     // refactored away and this isn't necessary.
@@ -653,6 +658,8 @@ class CONTENT_EXPORT IndexedDBBackingStore {
   // Can run a journal cleaning job if one is pending.
   void DidCommitTransaction();
 
+  SEQUENCE_CHECKER(idb_sequence_checker_);
+
   Mode backing_store_mode_;
   TransactionalLevelDBFactory* const transactional_leveldb_factory_;
   const url::Origin origin_;