Add accessible names to the launcher buttons

ash/launcher/app_launcher_button.cc

Index: ash/launcher/app_launcher_button.cc
diff --git a/ash/launcher/app_launcher_button.cc b/ash/launcher/app_launcher_button.cc
index ae23d19983d5f2f6d3f18260ea64c92419be2880..cc732550425c727d5d61b6d62d961411bf6626d4 100644
--- a/ash/launcher/app_launcher_button.cc
+++ b/ash/launcher/app_launcher_button.cc
@@ -7,6 +7,7 @@
 #include <algorithm>
 
 #include "ash/launcher/launcher_button_host.h"
+#include "ui/base/accessibility/accessible_view_state.h"
 #include "ui/gfx/canvas_skia.h"
 
 namespace ash {
@@ -81,5 +82,10 @@ void AppLauncherButton::OnMouseExited(const views::MouseEvent& event) {
   host_->MouseExitedButton(this);
 }
 
+void AppLauncherButton::GetAccessibleState(ui::AccessibleViewState* state) {
+  state->role = ui::AccessibilityTypes::ROLE_PUSHBUTTON;
+  state->name = host_->GetAccessibleName(this);
+}
+
 }  // namespace internal
 }  // namespace ash