[Hotword] Remove unneeded preferences. Cleaning up look of settings.

chrome/common/pref_names.cc

Index: chrome/common/pref_names.cc
diff --git a/chrome/common/pref_names.cc b/chrome/common/pref_names.cc
index b1b23cc5244cbd8c31a50e998fc203f525a0d824..82af284d3c6da7862228cc89f47fd46fbaabf361 100644
--- a/chrome/common/pref_names.cc
+++ b/chrome/common/pref_names.cc
@@ -2079,21 +2079,12 @@ const char kVideoCaptureAllowedUrls[] = "hardware.video_capture_allowed_urls";
 // trigger.
 const char kHotwordSearchEnabled[] = "hotword.search_enabled";
 
-// A boolean pref that controls the enabled-state of hotword search voice
-// trigger when using incognito mode.
-const char kHotwordSearchIncognitoEnabled[] =
-    "hotword.incognito_search_enabled";
-
 // An integer pref that keeps track of how many times the opt in popup for
 // hotword void search has been shown to the user. After this pref has reached
 // the maximum number of times as defined by the HotwordService, the popup is no
 // longer shown.
 const char kHotwordOptInPopupTimesShown[] = "hotword.opt_in_popup_times_shown";
 
-// A boolean pref that controls whether hotword search voice trigger stops
-// listening after 5 minutes.
-const char kHotwordSearchTimeoutEnabled[] = "hotword.search_timeout_enabled";
-
 #if defined(OS_ANDROID)
 // Boolean that controls the global enabled-state of protected media identifier.
 const char kProtectedMediaIdentifierEnabled[] =