Implement media cast buttons

Source/core/accessibility/AXMediaControls.cpp

Index: Source/core/accessibility/AXMediaControls.cpp
diff --git a/Source/core/accessibility/AXMediaControls.cpp b/Source/core/accessibility/AXMediaControls.cpp
index 5901add3951025d0cb31da1a3f9031cd35f4999f..854caac71c6c775b55cc2f366cdfd85429020e36 100644
--- a/Source/core/accessibility/AXMediaControls.cpp
+++ b/Source/core/accessibility/AXMediaControls.cpp
@@ -111,6 +111,10 @@ String AccessibilityMediaControl::accessibilityDescription() const
         return queryString(WebLocalizedString::AXMediaShowClosedCaptionsButton);
     case MediaHideClosedCaptionsButton:
         return queryString(WebLocalizedString::AXMediaHideClosedCaptionsButton);
+    case MediaCastOffButton:
+        return queryString(WebLocalizedString::AxMediaCastOffButton);
+    case MediaCastOnButton:
+        return queryString(WebLocalizedString::AxMediaCastOnButton);
     default:
         return queryString(WebLocalizedString::AXMediaDefault);
     }
@@ -141,6 +145,10 @@ String AccessibilityMediaControl::helpText() const
         return queryString(WebLocalizedString::AXMediaShowClosedCaptionsButtonHelp);
     case MediaHideClosedCaptionsButton:
         return queryString(WebLocalizedString::AXMediaHideClosedCaptionsButtonHelp);
+    case MediaCastOffButton:
+        return queryString(WebLocalizedString::AxMediaCastOffButtonHelp);
+    case MediaCastOnButton:
+        return queryString(WebLocalizedString::AxMediaCastOnButtonHelp);
     default:
         return queryString(WebLocalizedString::AXMediaDefault);
     }