Linux: implement ShouldRenderRichAnimation() based on $DISPLAY.

app/animation.cc

 // Copyright (c) 2006-2008 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "app/animation.h"
 
 #include "base/message_loop.h"
 
 #if defined(OS_WIN)
 #include "base/win_util.h"
@@ skipping 124 matching lines @@
     // Get "Turn off all unnecessary animations" value.
     if (::SystemParametersInfo(SPI_GETCLIENTAREAANIMATION, 0, &result, 0)) {
       // There seems to be a typo in the MSDN document (as of May 2009):
       //   http://msdn.microsoft.com/en-us/library/ms724947(VS.85).aspx
       // The document states that the result is TRUE when animations are
       // _disabled_, but in fact, it is TRUE when they are _enabled_.
       return !!result;
     }
   }
   return !::GetSystemMetrics(SM_REMOTESESSION);
+#elif defined(OS_LINUX)
+  char* display = getenv("DISPLAY");
+  return display && *display == ':';
 #endif
   return true;
 }