Removing useless Win7 checks + standardize its use

chrome/browser/prefs/incognito_mode_prefs.cc

Index: chrome/browser/prefs/incognito_mode_prefs.cc
diff --git a/chrome/browser/prefs/incognito_mode_prefs.cc b/chrome/browser/prefs/incognito_mode_prefs.cc
index b5324b392c822ef6665b0a81120c2cbeb05005b6..d00d33a7c12502a95bd24d878043de29e6c1724e 100644
--- a/chrome/browser/prefs/incognito_mode_prefs.cc
+++ b/chrome/browser/prefs/incognito_mode_prefs.cc
@@ -29,7 +29,6 @@
 #include "base/bind_helpers.h"
 #include "base/memory/singleton.h"
 #include "base/win/scoped_comptr.h"
-#include "base/win/windows_version.h"
 #endif  // OS_WIN
 
 #if defined(OS_ANDROID)
@@ -77,10 +76,6 @@ class PlatformParentalControlsValue {
     // Since we can potentially block, make sure the thread is okay with this.
     base::ThreadRestrictions::AssertIOAllowed();
 
-    // Query this info on Windows 7 and above.
-    if (base::win::GetVersion() < base::win::VERSION_WIN7)
-      return false;
-
     ThreadType thread_type = ThreadType::BLOCKING;
     if (BrowserThread::IsThreadInitialized(BrowserThread::UI) &&
         content::BrowserThread::CurrentlyOn(content::BrowserThread::UI)) {