Avoid CHECK against prefixed keys in WrapWithPrefixPrefStore

Currently, calling any getter/setter in WrapWithPrefixPrefStore with a
key prefixed with "the" prefix (the one that WrapWithPrefixPrefStore
works on), leads to a CHECK failure. However, WrapWithPrefixPrefStore
should not disallow having a pref with the prefix as a key, and it
should be the responsibility of the owner to ensure the prefix is not
used as a pref, if needed.

Bug: 336776819
Change-Id: I3c94ffa34696f3c1a5e804a7bc96a3b469907bc3
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/5563686
Auto-Submit: Ankush Singh <ankushkush@google.com>
Reviewed-by: Dominic Battré <battre@chromium.org>
Commit-Queue: Ankush Singh <ankushkush@google.com>
Cr-Commit-Position: refs/heads/main@{#1312780}

components/prefs/wrap_with_prefix_pref_store.cc

@@ -155,7 +155,6 @@ void WrapWithPrefixPrefStore::OnInitializationCompleted(bool succeeded) {
 
 std::string WrapWithPrefixPrefStore::AddDottedPrefix(
     std::string_view path) const {
-  CHECK(!HasDottedPrefix(path));
   return base::StrCat({dotted_prefix_, path});
 }
 

components/prefs/wrap_with_prefix_pref_store.h

@@ -31,6 +31,8 @@
 //
 // This can be used to merge separate pref stores into one single storage under
 // separate dictionary items.
+//
+// NOTE: Users are responsible for ensuring the prefix is not an existing pref.
 class COMPONENTS_PREFS_EXPORT WrapWithPrefixPrefStore
     : public PersistentPrefStore,
       public PrefStore::Observer {

components/prefs/wrap_with_prefix_pref_store_unittest.cc

@@ -394,6 +394,23 @@ TEST_F(WrapWithPrefixPrefStoreTest, HasReadErrorDelegateWithNullDelegate) {
   EXPECT_TRUE(store().HasReadErrorDelegate());
 }
 
+TEST_F(WrapWithPrefixPrefStoreTest, GetValueForPrefixedKeyIfNonExisting) {
+  target_store().SetString(kPrefixedTestPref, "value");
+  EXPECT_FALSE(store().GetValue(kPrefixedTestPref, nullptr));
+}
+
+TEST_F(WrapWithPrefixPrefStoreTest, GetValueForExistingIfExisting) {
+  target_store().SetString("prefixed.prefixed.test.pref", "value");
+  EXPECT_TRUE(ValueInStoreIs(store(), kPrefixedTestPref, "value"));
+}
+
+TEST_F(WrapWithPrefixPrefStoreTest, SetValueForPrefixedKey) {
+  EXPECT_CALL(observer_, OnPrefValueChanged(kPrefixedTestPref));
+
+  store().SetValue(kPrefixedTestPref, base::Value("value"), /*flags=*/0);
+  EXPECT_TRUE(ValueInStoreIs(store(), kPrefixedTestPref, "value"));
+}
+
 using WrapWithPrefixPrefStoreDeathTest = WrapWithPrefixPrefStoreTest;
 
 TEST_F(WrapWithPrefixPrefStoreDeathTest,