Add a button to open TalkBack settings in chrome://settings.

chrome/browser/ui/webui/options/browser_options_handler.cc

Index: chrome/browser/ui/webui/options/browser_options_handler.cc
diff --git a/chrome/browser/ui/webui/options/browser_options_handler.cc b/chrome/browser/ui/webui/options/browser_options_handler.cc
index 91f9c066b7730d0d0b561626d45dd8ab2f7b619d..42460e79a6d7381f16233af104d077260755525b 100644
--- a/chrome/browser/ui/webui/options/browser_options_handler.cc
+++ b/chrome/browser/ui/webui/options/browser_options_handler.cc
@@ -430,6 +430,8 @@ void BrowserOptionsHandler::GetLocalizedValues(base::DictionaryValue* values) {
       IDS_OPTIONS_SETTINGS_ACCESSIBILITY_STICKY_KEYS_DESCRIPTION },
     { "accessibilitySwitchAccess",
       IDS_OPTIONS_SETTINGS_ACCESSIBILITY_SWITCH_ACCESS_DESCRIPTION },
+    { "accessibilityTalkBackSettings",
+      IDS_OPTIONS_SETTINGS_ACCESSIBILITY_TALKBACK_SETTINGS },
     { "accessibilityTapDragging",
       IDS_OPTIONS_SETTINGS_ACCESSIBILITY_TOUCHPAD_TAP_DRAGGING_DESCRIPTION },
     { "accessibilityVirtualKeyboard",
@@ -800,6 +802,10 @@ void BrowserOptionsHandler::RegisterMessages() {
       "showAndroidAppsSettings",
       base::Bind(&BrowserOptionsHandler::ShowAndroidAppsSettings,
                  base::Unretained(this)));
+  web_ui()->RegisterMessageCallback(
+      "showAccessibilityTalkBackSettings",
+      base::Bind(&BrowserOptionsHandler::ShowAccessibilityTalkBackSettings,
+                 base::Unretained(this)));
 #else
   web_ui()->RegisterMessageCallback(
       "becomeDefaultBrowser",
@@ -1934,6 +1940,18 @@ void BrowserOptionsHandler::ShowAndroidAppsSettings(
   arc::LaunchAndroidSettingsApp(profile);
 }
 
+void BrowserOptionsHandler::ShowAccessibilityTalkBackSettings(
+    const base::ListValue *args) {
+  Profile* profile = Profile::FromWebUI(web_ui());
+  // Settings in secondary profile cannot access ARC.
+  if (!arc::ArcAuthService::IsAllowedForProfile(profile)) {
+    LOG(ERROR) << "Settings can't be invoked for non-primary profile";

[stevenjb, 2016/08/08 22:41:03]

Can this legitimately happen? If so it should just be a warning or vlog even. If
not it should be a DCHECK.

[yhanada, 2016/08/09 06:29:40]

I changed it to LOG(WARNING). Done.

+    return;
+  }
+
+  arc::ShowTalkBackSettings();
+}
+
 void BrowserOptionsHandler::SetupAccessibilityFeatures() {
   PrefService* pref_service = g_browser_process->local_state();
   base::FundamentalValue virtual_keyboard_enabled(