scanner: Add accessible names for selected region and fine tune handles.

Add accessible names so that screen readers can convey instructions for
adjusting the selected region.

Bug: b:398914045, b:401066100
Change-Id: I091676e1a5d1320baf8dfcb9b07a8d08d0536e1e
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/6379264
Reviewed-by: Elijah Hewer <hewer@chromium.org>
Reviewed-by: Min Chen <minch@chromium.org>
Commit-Queue: Michelle Chen <michellegc@google.com>
Cr-Commit-Position: refs/heads/main@{#1436425}

ash/ash_strings.grd

@@ -6764,6 +6764,12 @@ Here are some things you can try to get started.
       <message name="IDS_ASH_SCREEN_CAPTURE_ALERT_WINDOW_RECORD" desc="Alert spoken by screen readers on recording window screen.">
         Press enter to record window: <ph name="WINDOW_TITLE">$1<ex>Text</ex></ph>
       </message>
+      <message name="IDS_ASH_SCREEN_CAPTURE_SELECTED_AREA_ACCESSIBLE_NAME" desc="The accessible name of the selected region in capture mode.">
+        Selected area, use arrow keys to move
+      </message>
+      <message name="IDS_ASH_SCREEN_CAPTURE_SELECTED_DRAG_HANDLE_ACCESSIBLE_TITLE" desc="The accessible name of a drag handle that can be used to adjust the selected region in capture mode.">
+        Selected handle, use arrow keys to move
+      </message>
       <message name="IDS_ASH_SCREEN_CAPTURE_ALERT_SELECT_TYPE_IMAGE" desc="Alert spoken by screen readers on selecting screenshot mode.">
         Screenshot mode selected
       </message>

ash/ash_strings_grd/IDS_ASH_SCREEN_CAPTURE_SELECTED_AREA_ACCESSIBLE_NAME.png.sha1

@@ -0,0 +1 @@
+c2f78bcef81a412b272c4e71cd38d20ee928a8d1

ash/ash_strings_grd/IDS_ASH_SCREEN_CAPTURE_SELECTED_DRAG_HANDLE_ACCESSIBLE_TITLE.png.sha1

@@ -0,0 +1 @@
+f3727b727a478754098bdea6deae7463acea1a12

ash/capture_mode/capture_mode_session_focus_cycler.cc

@@ -25,6 +25,7 @@
 #include "ash/capture_mode/search_results_panel.h"
 #include "ash/public/cpp/shell_window_ids.h"
 #include "ash/shell.h"
+#include "ash/strings/grit/ash_strings.h"
 #include "ash/style/pill_button.h"
 #include "ash/style/style_util.h"
 #include "ash/style/tab_slider_button.h"
@@ -35,6 +36,7 @@
 #include "base/memory/raw_ptr.h"
 #include "chromeos/ui/base/chromeos_ui_constants.h"
 #include "ui/base/class_property.h"
+#include "ui/base/l10n/l10n_util.h"
 #include "ui/events/event.h"
 #include "ui/events/event_constants.h"
 #include "ui/events/keycodes/keyboard_codes.h"
@@ -272,6 +274,14 @@ bool IsCaptureWindowSelectable(aura::Window* window) {
   return !IsWindowFullyOccluded(window);
 }
 
+std::u16string GetA11yNameForFineTunePosition(
+    FineTunePosition fine_tune_position) {
+  return l10n_util::GetStringUTF16(
+      fine_tune_position == FineTunePosition::kCenter
+          ? IDS_ASH_SCREEN_CAPTURE_SELECTED_AREA_ACCESSIBLE_NAME
+          : IDS_ASH_SCREEN_CAPTURE_SELECTED_DRAG_HANDLE_ACCESSIBLE_TITLE);
+}
+
 }  // namespace
 
 // -----------------------------------------------------------------------------
@@ -657,8 +667,8 @@ void CaptureModeSessionFocusCycler::AdvanceFocus(bool reverse) {
       auto ax_virtual_view = std::make_unique<views::AXVirtualView>();
       ax_virtual_views_[fine_tune_position] = ax_virtual_view.get();
       ax_virtual_view->SetRole(ax::mojom::Role::kButton);
-      // TODO(crbug.com/401066100): Add strings.
+      ax_virtual_view->SetName(
-      ax_virtual_view->SetName(u"To be determined");
+          GetA11yNameForFineTunePosition(fine_tune_position));
       const views::AXVirtualView::AXVirtualViews& ax_virtual_children =
           ax_widget_->GetRootView()->GetViewAccessibility().virtual_children();
       CHECK_EQ(ax_virtual_children.size(), 1u);