[Sharesheet] Add accessible names.

This CL adds accessible names to the buttons on the sharesheet
for screen readers.

Bug: 1131296
Change-Id: I4182b3ed982e9f4da7800502ab530e458f91dc58
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2423646Reviewed-by: Avi Drissman <avi@chromium.org>
Commit-Queue: Melissa Zhang <melzhang@chromium.org>
Cr-Commit-Position: refs/heads/master@{#810014}

chrome/browser/ui/views/sharesheet/sharesheet_expand_button.cc

@@ -47,13 +47,18 @@ SharesheetExpandButton::SharesheetExpandButton(views::ButtonListener* listener)
 void SharesheetExpandButton::SetDefaultView() {
   icon_->SetImage(
       gfx::CreateVectorIcon(kCaretDownIcon, kCaretIconSize, kLabelColor));
-  label_->SetText(l10n_util::GetStringUTF16(IDS_SHARESHEET_MORE_APPS_LABEL));
+  auto display_name = l10n_util::GetStringUTF16(IDS_SHARESHEET_MORE_APPS_LABEL);
+  label_->SetText(display_name);
+  SetAccessibleName(display_name);
 }
 
 void SharesheetExpandButton::SetExpandedView() {
   icon_->SetImage(
       gfx::CreateVectorIcon(kCaretUpIcon, kCaretIconSize, kLabelColor));
-  label_->SetText(l10n_util::GetStringUTF16(IDS_SHARESHEET_FEWER_APPS_LABEL));
+  auto display_name =
+      l10n_util::GetStringUTF16(IDS_SHARESHEET_FEWER_APPS_LABEL);
+  label_->SetText(display_name);
+  SetAccessibleName(display_name);
 }
 
 gfx::Size SharesheetExpandButton::CalculatePreferredSize() const {

chrome/browser/ui/views/sharesheet/sharesheet_target_button.cc

@@ -79,6 +79,7 @@ SharesheetTargetButton::SharesheetTargetButton(
   }
 
   AddChildView(std::move(label_view));
+  SetAccessibleName(display_name);
 
   SetFocusForPlatform();
 }