Chrome Version: 60.0.3077.0 (Developer Build) (64-bit)
OS: GNU/Linux

What steps will reproduce the problem?
(0) Make sure DCHECKS are allowed in your build (dcheck_always_on = true in your GN file)
(1) Visit https://rsolomakhin.github.io/autofill/
(2) Fill in the password form, submit
(3) Accept the offer to save the passwords

What is the expected result?
No crash.

What happens instead?
The following DCHECK in FormStructure::EncodeUploadRequest fires:

      DCHECK(type == UNKNOWN_TYPE || type == EMPTY_TYPE ||
             available_field_types.count(type));

The value of |type| is 75 (PASSWORD), while available_field_types only contains 3, 5, 7, 9, 30, 33, 34, 35, 36, 77.

This DCHECK was originally added in https://codereview.chromium.org/6931029.

The call stack is:

autofill::FormStructure::EncodeUploadRequest()
autofill::AutofillDownloadManager::StartUploadRequest()
autofill::AutofillManager::UploadFormData()
_ZN4base8internal13FunctorTraitsIMN8autofill15AutofillManagerEFvPKNS2_13FormStructureERKNS_9TimeTicksES9_S9_bEvE6InvokeIRKNS_7WeakPtrIS3_EEJPS4_S9_S9_S9_RKbEEEvSB_OT_DpOT0_
_ZN4base8internal7InvokerINS0_9BindStateIMN8autofill15AutofillManagerEFvPKNS3_13FormStructureERKNS_9TimeTicksESA_SA_bEJNS_7WeakPtrIS4_EENS0_12OwnedWrapperIS5_EES8_S8_S8_bEEEFvvEE3RunEPNS0_13BindStateBaseE
_ZNO4base8CallbackIFvvELNS_8internal8CopyModeE0ELNS2_10RepeatModeE0EE3RunEv
base::(anonymous namespace)::PostTaskAndReplyRelay::RunReplyAndSelfDestruct()
_ZNO4base8CallbackIFvvELNS_8internal8CopyModeE0ELNS2_10RepeatModeE0EE3RunEv
base::debug::TaskAnnotator::RunTask()
base::MessageLoop::RunTask()
base::MessageLoop::DeferOrRunPendingTask()
base::MessageLoop::DoWork()
base::(anonymous namespace)::WorkSourceDispatch()
g_main_context_dispatch
<unknown>
g_main_context_iteration
base::MessagePumpGlib::Run()
base::MessageLoop::RunHandler()
base::RunLoop::Run()
ChromeBrowserMainParts::MainMessageLoopRun()
content::BrowserMainLoop::RunMainMessageLoopParts()
content::BrowserMainRunnerImpl::Run()
content::BrowserMain()
content::RunNamedProcessTypeMain()
content::ContentMainRunnerImpl::Run()
service_manager::Main()
content::ContentMain()
ChromeMain
__libc_start_main