Steps to reproduce:

1. Open a URL like chrome-extension://mhjfbmdgcfjbbpaeojofohoefgiehjai/index.html (the inner PDF viewer extension) and press Ctrl-D to bookmark
2. Open MD Bookmarks
3. Double click the PDF viewer bookmark to open it

Expected behavior:

PDF UI should open (works correctly in the current BMM)

Actual behavior:

Browser crash!

Received signal 11 SEGV_MAPERR 000000000138
#0 0x7fa95b74d137 base::debug::StackTrace::StackTrace()
#1 0x7fa95b74ccaf base::debug::(anonymous namespace)::StackDumpSignalHandler()
#2 0x7fa95b476330 <unknown>
#3 0x55633a36ebc6 std::_Rb_tree<>::find()
#4 0x55633ad491a0 extensions::Extension::GetManifestData()
#5 0x55633ad6ab5c extensions::IncognitoInfo::IsSplitMode()
#6 0x55633aeac735 extensions::ExtensionTabUtil::OpenTab()
#7 0x55633ae7f84f extensions::TabsCreateFunction::Run()

Given the signature, this is probably something to do with running chrome.tabs.create from a WebUI context.