Set keys for SwitchAccessEventHandler to capture using accessibiltyPrivate API

chrome/browser/accessibility/accessibility_extension_api.cc

Index: chrome/browser/accessibility/accessibility_extension_api.cc
diff --git a/chrome/browser/accessibility/accessibility_extension_api.cc b/chrome/browser/accessibility/accessibility_extension_api.cc
index 62abc25566768286c5c722d2896334b09bbf0b2b..86e427db51ff9438be17bde2c4c83e39ef229623 100644
--- a/chrome/browser/accessibility/accessibility_extension_api.cc
+++ b/chrome/browser/accessibility/accessibility_extension_api.cc
@@ -27,6 +27,7 @@
 #include "extensions/common/error_utils.h"
 #include "extensions/common/image_util.h"
 #include "extensions/common/manifest_handlers/background_info.h"
+#include "ui/events/keycodes/keyboard_codes.h"
 
 #if defined(OS_CHROMEOS)
 #include "chrome/browser/chromeos/accessibility/accessibility_manager.h"
@@ -164,3 +165,31 @@ AccessibilityPrivateDarkenScreenFunction::Run() {
 
   return RespondNow(Error(kErrorNotSupported));
 }
+
+#if defined(OS_CHROMEOS)
+ExtensionFunction::ResponseAction
+AccessibilityPrivateSetSwitchAccessKeysFunction::Run() {
+  std::unique_ptr<accessibility_private::SetSwitchAccessKeys::Params> params =
+      accessibility_private::SetSwitchAccessKeys::Params::Create(*args_);
+  EXTENSION_FUNCTION_VALIDATE(params);
+  std::vector<int> key_codes_list = params->key_codes;

[Devlin, 2017/06/02 02:02:36]

No need to copy this; prefer const std::vector<int>& (or just use
params->key_codes; it isn't used frequently and isn't that unreadable).

[elichtenberg, 2017/06/02 17:57:47]

Done.

+
+  // For now, only accept key code if it represents an alphanumeric character.
+  std::set<int> key_codes;
+  for (size_t i = 0; i < key_codes_list.size(); ++i) {

[Devlin, 2017/06/02 02:02:36]

prefer:
for (auto key_code : key_codes_list) {
  EXTENSION_FUNCTION_VALIDATE(...);
  key_codes.insert(key_code);
}

[elichtenberg, 2017/06/02 17:57:46]

Done.

+    int key_code = key_codes_list.at(i);
+    EXTENSION_FUNCTION_VALIDATE(key_code >= ui::VKEY_0 &&
+                                key_code <= ui::VKEY_Z);
+    key_codes.insert(key_code);
+  }
+
+  chromeos::AccessibilityManager* manager =
+      chromeos::AccessibilityManager::Get();
+
+  // AccessibilityManager can be null during system shut down, but no need to
+  // return error in this case, so just check that manager is not null.
+  if (manager)
+    manager->SetSwitchAccessKeys(key_codes);
+  return RespondNow(NoArguments());
+}
+#endif  // defined (OS_CHROMEOS)