sensors: Remove prototype implementation

chrome/browser/chrome_browser_main_extra_parts_ash.cc

Index: chrome/browser/chrome_browser_main_extra_parts_ash.cc
diff --git a/chrome/browser/chrome_browser_main_extra_parts_ash.cc b/chrome/browser/chrome_browser_main_extra_parts_ash.cc
index 9f1a582812c7b6aaacc0326a97d0557028589e4c..fc1bddd6896ded617f2cf6e001e644d9cabf3121 100644
--- a/chrome/browser/chrome_browser_main_extra_parts_ash.cc
+++ b/chrome/browser/chrome_browser_main_extra_parts_ash.cc
@@ -15,7 +15,6 @@
 #include "chrome/browser/ui/views/ash/caps_lock_handler.h"
 #include "chrome/browser/ui/views/ash/chrome_shell_delegate.h"
 #include "chrome/browser/ui/views/ash/key_rewriter.h"
-#include "chrome/browser/ui/views/ash/screen_orientation_listener.h"
 #include "chrome/browser/ui/views/ash/screenshot_taker.h"
 #include "chrome/browser/ui/views/ash/user_gesture_handler.h"
 #include "ui/aura/env.h"
@@ -81,10 +80,6 @@ void ChromeBrowserMainExtraPartsAsh::PreProfileInit() {
       switches::kDisableZeroBrowsersOpenForTests))
     BrowserList::StartKeepAlive();
 #endif
-
-  // Make sure the singleton ScreenOrientationListener object is created.
-  ScreenOrientationListener::GetInstance();
-
   gesture_handler_.reset(new UserGestureHandler);
   aura::client::SetUserGestureClient(
       ash::Shell::GetRootWindow(), gesture_handler_.get());