[omnibox] [rich-autocomplete] Add AutocompleteMatch::EmptyAutocompletion

Just a helper to check if both suffix and prefix autocompletion are
empty. This is in preparation for the potential introduction of a 3rd
autocompletion field.

Bug: 1062446
Change-Id: I58aecb9cffb690618bb835ed97e1cb69cfdae635
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2426964
Commit-Queue: manuk hovanesian <manukh@chromium.org>
Reviewed-by: Tommy Li <tommycli@chromium.org>
Cr-Commit-Position: refs/heads/master@{#810248}

components/omnibox/browser/autocomplete_match.cc

@@ -1040,7 +1040,7 @@ AutocompleteMatch::GetMatchWithContentsAndDescriptionPossiblySwapped() const {
 }
 
 void AutocompleteMatch::SetAllowedToBeDefault(const AutocompleteInput& input) {
-  if (inline_autocompletion.empty() && prefix_autocompletion.empty())
+  if (IsEmptyAutocompletion())
     allowed_to_be_default_match = true;
   else if (input.prevent_inline_autocomplete())
     allowed_to_be_default_match = false;
@@ -1129,7 +1129,7 @@ void AutocompleteMatch::UpgradeMatchWithPropertiesFrom(
       fill_into_edit == duplicate_match.fill_into_edit &&
       duplicate_match.allowed_to_be_default_match) {
     allowed_to_be_default_match = true;
-    if (inline_autocompletion.empty() && prefix_autocompletion.empty()) {
+    if (IsEmptyAutocompletion()) {
       inline_autocompletion = duplicate_match.inline_autocompletion;
       prefix_autocompletion = duplicate_match.prefix_autocompletion;
     }
@@ -1254,6 +1254,10 @@ bool AutocompleteMatch::TryRichAutocompletion(
   return false;
 }
 
+bool AutocompleteMatch::IsEmptyAutocompletion() const {
+  return inline_autocompletion.empty() && prefix_autocompletion.empty();
+}
+
 #if DCHECK_IS_ON()
 void AutocompleteMatch::Validate() const {
   std::string provider_name = provider ? provider->GetName() : "None";

components/omnibox/browser/autocomplete_match.h

@@ -446,6 +446,9 @@ struct AutocompleteMatch {
                              const AutocompleteInput& input,
                              bool shortcut_provider = false);
 
+  // True if both |inline_autocompletion| & |prefix_autocompletion| are empty.
+  bool IsEmptyAutocompletion() const;
+
   // The provider of this match, used to remember which provider the user had
   // selected when the input changes. This may be NULL, in which case there is
   // no provider (or memory of the user's selection).