Assume all providers may give zero suggest responses.

components/omnibox/keyword_provider.cc

Index: components/omnibox/keyword_provider.cc
diff --git a/components/omnibox/keyword_provider.cc b/components/omnibox/keyword_provider.cc
index d8754e9f14dcf19f9c2d37b7f7349a68c93a5325..25807773a61ab932d7116e6a20c58e8b8426ab8c 100644
--- a/components/omnibox/keyword_provider.cc
+++ b/components/omnibox/keyword_provider.cc
@@ -199,7 +199,8 @@ AutocompleteMatch KeywordProvider::CreateVerbatimMatch(
 }
 
 void KeywordProvider::Start(const AutocompleteInput& input,
-                            bool minimal_changes) {
+                            bool minimal_changes,
+                            bool called_due_to_focus) {
   // This object ensures we end keyword mode if we exit the function without
   // toggling keyword mode to on.
   ScopedEndExtensionKeywordMode keyword_mode_toggle(extensions_delegate_.get());
@@ -215,6 +216,9 @@ void KeywordProvider::Start(const AutocompleteInput& input,
       extensions_delegate_->IncrementInputId();
   }
 
+  if (called_due_to_focus)
+    return;
+
   // Split user input into a keyword and some query input.
   //
   // We want to suggest keywords even when users have started typing URLs, on