add --enable-spatial-navigation flag for testing

This depends on the following blink patch:
https://codereview.chromium.org/13811041/

Review URL: https://chromiumcodereview.appspot.com/14110006

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@194875 0039d316-1c4b-4281-b951-d872f2087c98
diff --git a/content/browser/web_contents/web_contents_impl.cc b/content/browser/web_contents/web_contents_impl.cc
index 1cc9efeb..72ff14b9 100644
--- a/content/browser/web_contents/web_contents_impl.cc
+++ b/content/browser/web_contents/web_contents_impl.cc
@@ -592,6 +592,9 @@
       command_line.HasSwitch(switches::kEnableDeferredImageDecoding) ||
       cc::switches::IsImplSidePaintingEnabled();
 
+  prefs.spatial_navigation_enabled = command_line.HasSwitch(
+      switches::kEnableSpatialNavigation);
+
   GetContentClient()->browser()->OverrideWebkitPrefs(rvh, url, &prefs);
 
   // Disable compositing in guests until we have compositing path implemented