Revert r162691 "Fix for out-of-sync scale factor issue"

chrome/browser/ui/startup/startup_browser_creator_impl.cc

Index: chrome/browser/ui/startup/startup_browser_creator_impl.cc
diff --git a/chrome/browser/ui/startup/startup_browser_creator_impl.cc b/chrome/browser/ui/startup/startup_browser_creator_impl.cc
index daec2d31c313cbcffc27b22a36458ecc8ddc63c4..d6b0d4101fbb7925452af2bea314f89d960f7953 100644
--- a/chrome/browser/ui/startup/startup_browser_creator_impl.cc
+++ b/chrome/browser/ui/startup/startup_browser_creator_impl.cc
@@ -97,8 +97,6 @@
 
 #if defined(USE_ASH)
 #include "ash/launcher/launcher_types.h"
-#include "ash/shell.h"
-#include "ui/aura/window.h"
 #endif
 
 #if defined(OS_MACOSX)
@@ -808,20 +806,6 @@ Browser* StartupBrowserCreatorImpl::OpenTabsInBrowser(Browser* browser,
 #endif
   }
 
-#if defined(USE_ASH)
-  if (ash::Shell::HasInstance()) {
-    // Set the browser's root window to be an active root window now so
-    // that that web contents can determine correct scale factor for the
-    // renderer. This is a short term fix for crbug.com/155201.  Without
-    // this, the renderer may use wrong scale factor first, then
-    // switched to the correct scale factor, which can cause race
-    // condition and lead to the results rendered at wrong scale factor.
-    // Long term fix is tracked in crbug.com/15543.
-    ash::Shell::GetInstance()->set_active_root_window(
-        browser->window()->GetNativeWindow()->GetRootWindow());
-  }
-#endif
-
   // In kiosk mode, we want to always be fullscreen, so switch to that now.
   if (CommandLine::ForCurrentProcess()->HasSwitch(switches::kKioskMode))
     chrome::ToggleFullscreenMode(browser);