autotest: Increase Chrome first-render timeout

Change-Id: I9fa4c32d2dfe83e13192ba661476930208a8ca63

BUG=
TEST=

Review URL: http://codereview.chromium.org/3455025
diff --git a/client/site_tests/desktopui_ChromeFirstRender/desktopui_ChromeFirstRender.py b/client/site_tests/desktopui_ChromeFirstRender/desktopui_ChromeFirstRender.py
index 9b0c03d..7cc4b2d 100644
--- a/client/site_tests/desktopui_ChromeFirstRender/desktopui_ChromeFirstRender.py
+++ b/client/site_tests/desktopui_ChromeFirstRender/desktopui_ChromeFirstRender.py
@@ -26,7 +26,8 @@
                 site_login.TimeoutError('Timed out waiting for initial login'))
             site_utils.poll_for_condition(
                 lambda: os.access(self._FIRST_RENDER_FILE, os.F_OK),
-                site_login.TimeoutError('Timed out waiting for initial render'))
+                site_login.TimeoutError('Timed out waiting for initial render'),
+                timeout=60)
 
             start_time = self.__parse_uptime(self._LOGIN_SUCCESS_FILE)
             end_time = self.__parse_uptime(self._FIRST_RENDER_FILE)