[IndexedDB] Delete callbacks state on worker thread exit.

content/child/indexed_db/indexed_db_dispatcher.cc

Index: content/child/indexed_db/indexed_db_dispatcher.cc
diff --git a/content/child/indexed_db/indexed_db_dispatcher.cc b/content/child/indexed_db/indexed_db_dispatcher.cc
index aafd24419d65f749c47d08f81e01134920406d48..a014c96391a6c6003abe8c12d10992e5d9dfbb43 100644
--- a/content/child/indexed_db/indexed_db_dispatcher.cc
+++ b/content/child/indexed_db/indexed_db_dispatcher.cc
@@ -196,24 +196,28 @@ void IndexedDBDispatcher::CursorDestroyed(int32_t ipc_cursor_id) {
 
 void IndexedDBDispatcher::RegisterMojoOwnedCallbacks(
     IndexedDBCallbacksImpl::InternalState* callbacks) {
-  mojo_owned_callback_state_.insert(callbacks);
+  mojo_owned_callback_state_[callbacks] = base::WrapUnique(callbacks);
 }
 
 void IndexedDBDispatcher::UnregisterMojoOwnedCallbacks(
     IndexedDBCallbacksImpl::InternalState* callbacks) {
-  DCHECK(base::ContainsValue(mojo_owned_callback_state_, callbacks));
-  mojo_owned_callback_state_.erase(callbacks);
+  auto it = mojo_owned_callback_state_.find(callbacks);
+  DCHECK(it != mojo_owned_callback_state_.end());
+  it->second.release();

[jsbell, 2016/11/21 22:38:06]

Is the release() necessary?

[Reilly Grant (use Gerrit), 2016/11/21 23:26:10]

Yes. Otherwise erase(it) will free the object and that would be bad because this
is called from within the object's destructor.

[jsbell, 2016/11/21 23:36:29]

Derp. My brain was reading `reset()` for some reason.

+  mojo_owned_callback_state_.erase(it);
 }
 
 void IndexedDBDispatcher::RegisterMojoOwnedDatabaseCallbacks(
     blink::WebIDBDatabaseCallbacks* callbacks) {
-  mojo_owned_database_callback_state_.insert(callbacks);
+  mojo_owned_database_callback_state_[callbacks] = base::WrapUnique(callbacks);
 }
 
 void IndexedDBDispatcher::UnregisterMojoOwnedDatabaseCallbacks(
     blink::WebIDBDatabaseCallbacks* callbacks) {
-  DCHECK(base::ContainsValue(mojo_owned_database_callback_state_, callbacks));
-  mojo_owned_database_callback_state_.erase(callbacks);
+  auto it = mojo_owned_database_callback_state_.find(callbacks);
+  DCHECK(it != mojo_owned_database_callback_state_.end());
+  it->second.release();
+  mojo_owned_database_callback_state_.erase(it);
 }
 
 // Populate some WebIDBValue members (data & blob info) from the supplied