[omnibox] Adding a11y voiceover for when we're in keyword mode

Currently, there is no voiceover to indicate when we're in keyword mode.
This CL expands the existing voiceover for keyword button focus
to apply to all of keyword mode.

Bug: 785375
Change-Id: I8d284395848e5f092d4ab0a855d23e80bef10c70
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2411230Reviewed-by: Tommy Li <tommycli@chromium.org>
Reviewed-by: Aaron Leventhal <aleventhal@chromium.org>
Commit-Queue: Angela Yoeurng <yoangela@chromium.org>
Cr-Commit-Position: refs/heads/master@{#809114}

chrome/browser/ui/views/omnibox/omnibox_suggestion_button_row_view.cc

@@ -167,7 +167,7 @@ void OmniboxSuggestionButtonRowView::UpdateFromModel() {
         keyword, edit_model->client()->GetTemplateURLService());
     keyword_button_->SetText(names.full_name);
     keyword_button_->SetAccessibleName(
-        l10n_util::GetStringFUTF16(IDS_ACC_KEYWORD_BUTTON, names.short_name));
+        l10n_util::GetStringFUTF16(IDS_ACC_KEYWORD_MODE, names.short_name));
   }
 
   SetPillButtonVisibility(tab_switch_button_,

components/omnibox/browser/omnibox_popup_model.cc

@@ -617,11 +617,7 @@ base::string16 OmniboxPopupModel::GetAccessibilityLabelForCurrentSelection(
       break;
     }
     case KEYWORD_MODE:
-      if (OmniboxFieldTrial::IsKeywordSearchButtonEnabled()) {
-        additional_message_id = IDS_ACC_KEYWORD_BUTTON;
-      }
-      // TODO(tommycli): Investigate whether the accessibility messaging for
-      // (non-button row) Keyword mode belongs here.
+      additional_message_id = IDS_ACC_KEYWORD_MODE;
       break;
     case FOCUSED_BUTTON_TAB_SWITCH:
       additional_message_id = IDS_ACC_TAB_SWITCH_BUTTON_FOCUSED_PREFIX;

components/omnibox_strings.grdp

@@ -254,8 +254,8 @@
     <message name="IDS_ACC_KEYWORD_SUFFIX" desc="Suffix for spoken keyword suggestion description to explain keystroke used to search.">
     <ph name="KEYWORD_FOCUSED_FRIENDLY_MATCH_TEXT">$1<ex>The Chromium Projects http://www.chromium.org bookmark</ex></ph>, press Tab then Enter to search
   </message>
-  <message name="IDS_ACC_KEYWORD_BUTTON" desc="Announcement when keyword search button focused.">
-    Search button, press Enter to search <ph name="KEYWORD_SUFFIX">$1<ex>Youtube</ex></ph>
+  <message name="IDS_ACC_KEYWORD_MODE" desc="Announcement when entering keyword search mode.">
+    Search mode, press Enter to search <ph name="KEYWORD_SUFFIX">$1<ex>Youtube</ex></ph>
   </message>
 
   <!-- Accessibility suffix for suggestions when the remove button is focused. -->