Fixes bug where deleting local history ZPS with Shit+Del doesn't update UI

Deleting suggestions with Shift+Del (as opposed to right click and choosing
delete from the dropdown menu) does not invoke Start() on the provider.
Therefore, the list of autocomplete matches were not being updated. This
fixes that bug by immediately deleting the match from the list of matches.

Bug: 996516
Change-Id: If37a59d80b68a9f64a66140328a49549ef8ae53d
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/1832983
Commit-Queue: Moe Ahmadi <mahmadi@chromium.org>
Reviewed-by: Tommy Li <tommycli@chromium.org>
Cr-Commit-Position: refs/heads/master@{#702225}

components/omnibox/browser/local_history_zero_suggest_provider.cc

@@ -234,6 +234,11 @@ void LocalHistoryZeroSuggestProvider::DeleteMatch(
   // Prevent the deleted suggestion from being resuggested until the
   // corresponding URLs are asynchronously deleted.
   deleted_suggestions_set_.insert(match.contents);
+
+  // Immediately update the list of matches to reflect the match was deleted.
+  base::EraseIf(matches_, [&](const auto& item) {
+    return match.contents == item.contents;
+  });
 }
 
 LocalHistoryZeroSuggestProvider::LocalHistoryZeroSuggestProvider(

components/omnibox/browser/local_history_zero_suggest_provider_unittest.cc

@@ -328,8 +328,11 @@ TEST_F(LocalHistoryZeroSuggestProviderTest, Delete) {
 
   provider_->DeleteMatch(provider_->matches()[0]);
 
-  // Make sure the deletion takes effect immediately in the provider even before
-  // the history service asynchronously performs the deletion.
+  // Make sure the deletion takes effect immediately in the provider before the
+  // history service asynchronously performs the deletion or even before the
+  // provider is started again.
+  ExpectMatches({});
+
   StartProviderAndWaitUntilDone();
   ExpectMatches({});