IndexedDB: Fix prefetching; cache was always being bypassed.

content/common/indexed_db/proxy_webidbcursor_impl.cc

Index: content/common/indexed_db/proxy_webidbcursor_impl.cc
diff --git a/content/common/indexed_db/proxy_webidbcursor_impl.cc b/content/common/indexed_db/proxy_webidbcursor_impl.cc
index f043356171fdbe58f43eac00908d79113b030043..5fa1c8703a60fbd1bab2eb1870728fa4d1b1e9be 100644
--- a/content/common/indexed_db/proxy_webidbcursor_impl.cc
+++ b/content/common/indexed_db/proxy_webidbcursor_impl.cc
@@ -26,6 +26,8 @@ RendererWebIDBCursorImpl::~RendererWebIDBCursorImpl() {
   // object since inside WebKit, they hold a reference to the object wich owns
   // this object. But, if that ever changed, then we'd need to invalidate
   // any such pointers.
+  if (idb_cursor_id_ == kInvalidIDBCursorId)
+    return;
   IndexedDBDispatcher::Send(new IndexedDBHostMsg_CursorDestroyed(
       idb_cursor_id_));
   IndexedDBDispatcher* dispatcher =
@@ -34,6 +36,8 @@ RendererWebIDBCursorImpl::~RendererWebIDBCursorImpl() {
 }
 
 unsigned short RendererWebIDBCursorImpl::direction() const {
+  if (idb_cursor_id_ == kInvalidIDBCursorId)
+    return 0;
   int direction;
   IndexedDBDispatcher::Send(
       new IndexedDBHostMsg_CursorDirection(idb_cursor_id_, &direction));
@@ -55,6 +59,8 @@ WebSerializedScriptValue RendererWebIDBCursorImpl::value() const {
 void RendererWebIDBCursorImpl::update(const WebSerializedScriptValue& value,
                                       WebIDBCallbacks* callbacks,
                                       WebExceptionCode& ec) {
+  if (idb_cursor_id_ == kInvalidIDBCursorId)
+    return;
   IndexedDBDispatcher* dispatcher =
       IndexedDBDispatcher::ThreadSpecificInstance();
   dispatcher->RequestIDBCursorUpdate(
@@ -67,7 +73,7 @@ void RendererWebIDBCursorImpl::continueFunction(const WebIDBKey& key,
   IndexedDBDispatcher* dispatcher =
       IndexedDBDispatcher::ThreadSpecificInstance();
 
-  if (key.type() == WebIDBKey::InvalidType) {
+  if (key.type() == WebIDBKey::NullType) {
     // No key, so this would qualify for a prefetch.
     ++continue_count_;
 
@@ -77,6 +83,9 @@ void RendererWebIDBCursorImpl::continueFunction(const WebIDBKey& key,
       return;
     }
 
+    if (idb_cursor_id_ == kInvalidIDBCursorId)
+      return;
+
     if (continue_count_ > kPrefetchContinueThreshold) {
       // Request pre-fetch.
       dispatcher->RequestIDBCursorPrefetch(prefetch_amount_, callbacks,
@@ -94,12 +103,17 @@ void RendererWebIDBCursorImpl::continueFunction(const WebIDBKey& key,
     ResetPrefetchCache();
   }
 
+  if (idb_cursor_id_ == kInvalidIDBCursorId)
+    return;
+
   dispatcher->RequestIDBCursorContinue(IndexedDBKey(key), callbacks,
                                        idb_cursor_id_, &ec);
 }
 
 void RendererWebIDBCursorImpl::deleteFunction(WebIDBCallbacks* callbacks,
                                               WebExceptionCode& ec) {
+  if (idb_cursor_id_ == kInvalidIDBCursorId)
+    return;
   IndexedDBDispatcher* dispatcher =
       IndexedDBDispatcher::ThreadSpecificInstance();
   dispatcher->RequestIDBCursorDelete(callbacks, idb_cursor_id_, &ec);
@@ -168,11 +182,14 @@ void RendererWebIDBCursorImpl::ResetPrefetchCache() {
     return;
   }
 
-  IndexedDBDispatcher* dispatcher =
-      IndexedDBDispatcher::ThreadSpecificInstance();
-  dispatcher->RequestIDBCursorPrefetchReset(used_prefetches_,
-                                            prefetch_keys_.size(),
-                                            idb_cursor_id_);
+  if (idb_cursor_id_ != kInvalidIDBCursorId) {
+    IndexedDBDispatcher* dispatcher =
+        IndexedDBDispatcher::ThreadSpecificInstance();
+    dispatcher->RequestIDBCursorPrefetchReset(used_prefetches_,
+                                              prefetch_keys_.size(),
+                                              idb_cursor_id_);
+  }
+
   prefetch_keys_.clear();
   prefetch_primary_keys_.clear();
   prefetch_values_.clear();