Enable the option to remove previous user PrefService

We need this change so we can replace the previous user PrefService
with a new one when changing the data path in QWebEngineProfile. If
we don't have this change, the code will assert.

This is required to properly fix QTBUG-75740.

Change-Id: I956f0b0549caf258cc49ac0818f6eca0ddcbafd7
Reviewed-by: Allan Sandfeld Jensen <allan.jensen@qt.io>

2 files changed, 13 insertions, 0 deletions

diff --git a/chromium/components/user_prefs/user_prefs.cc b/chromium/components/user_prefs/user_prefs.cc
index a752c8f8acc..dff5f2a258d 100644
--- a/chromium/components/user_prefs/user_prefs.cc
+++ b/chromium/components/user_prefs/user_prefs.cc
@@ -38,6 +38,15 @@ void UserPrefs::Set(base::SupportsUserData* context, PrefService* prefs) {
   context->SetUserData(UserDataKey(), base::WrapUnique(new UserPrefs(prefs)));
 }
 
+// static
+// TODO: Remove in Qt6 when contexts are only set once
+void UserPrefs::Remove(base::SupportsUserData* context) {
+  DCHECK(context);
+  DCHECK(context->GetUserData(UserDataKey()));
+  context->RemoveUserData(UserDataKey());
+}
+
+
 UserPrefs::UserPrefs(PrefService* prefs) : prefs_(prefs) {
 }
 
diff --git a/chromium/components/user_prefs/user_prefs.h b/chromium/components/user_prefs/user_prefs.h
index 392e5dc7f23..3a86997cf23 100644
--- a/chromium/components/user_prefs/user_prefs.h
+++ b/chromium/components/user_prefs/user_prefs.h
@@ -29,6 +29,10 @@ class USER_PREFS_EXPORT UserPrefs : public base::SupportsUserData::Data {
   // only once per context.
   static void Set(base::SupportsUserData* context, PrefService* prefs);
 
+  // Remove existing |prefs| on a |context|.
+  // TODO: Remove in Qt6 when contexts are only set once
+  static void Remove(base::SupportsUserData* context);
+
  private:
   explicit UserPrefs(PrefService* prefs);