More polish in prep for CrOS support

tools/gpu/gpu_tools/first_paint_time_benchmark.py

 # Copyright (c) 2012 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.
 
 # The test takes a list of URLs through stdin and prints results in CSV format.
 # Example: python run_scroll_test.py < data/urls.txt > test_results.csv
 import chrome_remote_control
 
 import multi_page_benchmark
 import util
 
 
 class FirstPaintTimeBenchmark(multi_page_benchmark.MultiPageBenchmark):
   def MeasurePage(self, page, tab):
+    if tab.browser.is_content_shell:
+      return {"first_paint_secs": "unsupported"}
+
     tab.runtime.Execute("""
         window.__rafFired = false;
         window.webkitRequestAnimationFrame(function() {
             window.__rafFired  = true;
         });
     """)
     chrome_remote_control.WaitFor(
         lambda: tab.runtime.Evaluate('window.__rafFired'), 60)
 
     first_paint_secs = tab.runtime.Evaluate(
-      'chrome.loadTimes().firstPaintTime - chrome.loadTimes().startLoadTime')
+      'window.chrome.loadTimes().firstPaintTime - ' +
+      'window.chrome.loadTimes().startLoadTime')
 
     return {
         "first_paint_secs": util.RoundTo3DecimalPlaces(first_paint_secs)
         }
 
 def Main():
   return multi_page_benchmark.Main(FirstPaintTimeBenchmark())