Temporarily disable in-browser thumbnailing on Win and Mac.

There is a regression caused by in-browser thumbnailin gon Win and Mac.
http://code.google.com/p/chromium/issues/detail?id=130916

I temporarily disable it until the cause of the regression is identified.

TBR=brettw
BUG=130916,120003
TEST=None

Review URL: https://chromiumcodereview.appspot.com/10544008

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@140596 0039d316-1c4b-4281-b951-d872f2087c98

chrome/common/thumbnail_support.cc

@@ -16,15 +16,9 @@ bool ShouldEnableInBrowserThumbnailing() {
           switches::kDisableInBrowserThumbnailing))
     return false;
 
-#if defined(OS_WIN)
-  // Disables in-browser thumbnailing on Windows XP where not supported yet.
-  if (base::win::GetVersion() < base::win::VERSION_VISTA)
-    return false;
+#if defined(OS_CHROMEOS)
   return true;
-#elif defined(OS_LINUX) && !defined(USE_AURA)
-  // Disables in-browser thumbnailing on non-Aura Linux where not supported yet.
-  return false;
 #else
-  return true;
+  return false;
 #endif
 }