tvOS: Make the accessibility extension code work in Chrobalt (youtube#9221)

The code in the tree came directly from C25 and did not build as-is.

* Remove the existing implementations of GetDisplaySettings(),
GetCaptionSettings() and SetCaptionsEnabled() and provide stub
implementations instead. These functions are part of the Starboard API
for the a11y extension but nothing in the tree calls them.
* Remove the nested namespaces that were removed from the tree in main.
* Provide a GetTextToSpeechSettings() implementation that does not use
code that was removed. Just query UIAccessibilityIsVoiceOverRunning() to
determine whether TTS is active or not.

Together with youtube#9219 (and a follow-up that enables the accessibility
extension), this should be enough code to make h5vcc_accessibility
determine whether VoiceOver is on or not on tvOS.

Bug: 478127016
Bug: 447135715

Co-authored-by: fayev-g <fayev@google.com>

Author: rakuco

starboard/tvos/shared/BUILD.gn

@@ -78,6 +78,9 @@ static_library("starboard_platform") {
     "//starboard/shared/starboard/window_set_default_options.cc",
     "//starboard/shared/stub/storage_write_record.cc",
     "//starboard/shared/stub/system_symbolize.cc",
+    "accessibility_extension.cc",
+    "accessibility_extension.h",
+    "accessibility_get_text_to_speech_settings.mm",
     "application_darwin.h",
     "application_darwin.mm",
     "configuration_constants.cc",

starboard/tvos/shared/accessibility_extension.cc

@@ -17,21 +17,36 @@
 #include "starboard/extension/accessibility.h"
 
 namespace starboard {
-namespace shared {
-namespace uikit {
+
+namespace {
+
+// The following functions are part of the Starboard API for this extension
+// but are not used anywhere in Chrobalt.
+
+bool GetDisplaySettings(SbAccessibilityDisplaySettings* out_setting) {
+  return false;
+}
+
+bool GetCaptionSettings(SbAccessibilityCaptionSettings* caption_settings) {
+  return false;
+}
+
+bool SetCaptionsEnabled(bool enabled) {
+  return false;
+}
+
+}  // namespace
 
 const StarboardExtensionAccessibilityApi kAccessibilityAPI = {
     kStarboardExtensionAccessibilityName,
     1,
-    &accessibility::GetTextToSpeechSettings,
-    &accessibility::GetDisplaySettings,
-    &accessibility::GetCaptionSettings,
-    &accessibility::SetCaptionsEnabled};
+    &GetTextToSpeechSettings,
+    &GetDisplaySettings,
+    &GetCaptionSettings,
+    &SetCaptionsEnabled};
 
 const void* GetAccessibilityApi() {
   return &kAccessibilityAPI;
 }
 
-}  // namespace uikit
-}  // namespace shared
 }  // namespace starboard

starboard/tvos/shared/accessibility_extension.h

@@ -18,25 +18,11 @@
 #include "starboard/extension/accessibility.h"
 
 namespace starboard {
-namespace shared {
-namespace uikit {
-
-namespace accessibility {
-
-bool GetCaptionSettings(SbAccessibilityCaptionSettings* caption_settings);
-
-bool GetDisplaySettings(SbAccessibilityDisplaySettings* out_setting);
 
 bool GetTextToSpeechSettings(SbAccessibilityTextToSpeechSettings* out_setting);
 
-bool SetCaptionsEnabled(bool enabled);
-
-}  // namespace accessibility
-
 const void* GetAccessibilityApi();
 
-}  // namespace uikit
-}  // namespace shared
 }  // namespace starboard
 
 #endif  // STARBOARD_TVOS_SHARED_ACCESSIBILITY_EXTENSION_H_

starboard/tvos/shared/accessibility_get_caption_settings.mm

@@ -12,35 +12,23 @@
 // See the License for the specific language governing permissions and
 // limitations under the License.
 
-#import <Foundation/Foundation.h>
+#import <UIKit/UIKit.h>
 
 #include "starboard/common/memory.h"
 #include "starboard/tvos/shared/accessibility_extension.h"
-#import "starboard/tvos/shared/speech_synthesizer.h"
-#import "starboard/tvos/shared/starboard_application.h"
 
 namespace starboard {
-namespace shared {
-namespace uikit {
-
-namespace accessibility {
 
 bool GetTextToSpeechSettings(SbAccessibilityTextToSpeechSettings* out_setting) {
   if (!out_setting ||
-      !starboard::common::MemoryIsZero(
-          out_setting, sizeof(SbAccessibilityTextToSpeechSettings))) {
+      !MemoryIsZero(out_setting, sizeof(SbAccessibilityTextToSpeechSettings))) {
     return false;
   }
 
-  @autoreleasepool {
-    out_setting->has_text_to_speech_setting = true;
-    out_setting->is_text_to_speech_enabled =
-        SBDGetApplication().speechSynthesizer.screenReaderActive;
-  }
+  out_setting->has_text_to_speech_setting = true;
+  out_setting->is_text_to_speech_enabled = UIAccessibilityIsVoiceOverRunning();
+
   return true;
 }
 
-}  // namespace accessibility
-}  // namespace uikit
-}  // namespace shared
 }  // namespace starboard