ShortcutsBackend initializes asynchronously. When clearBrowsingData() was
called during startup, the backend was still in the INITIALIZING state and
its OnHistoryDeletions handler silently returned early, leaving shortcut
suggestions (clock-icon entries) intact after exit.
Fix by adding a JNI bridge (BraveShortcutsUtils.initThenRun) that waits for
ShortcutsBackend to finish its async DB init via OnShortcutsLoaded() before
invoking clearBrowsingData(). Also move the clear-on-exit call from
initializeState() to finishNativeInitialization() where the profile is
available, and add FORM_DATA (autofill) to the cleared data types.
samartnik
380731a553