Add UMA datapoints for cases where FilterURL fails.

content/browser/renderer_host/render_view_host_impl.cc

Index: content/browser/renderer_host/render_view_host_impl.cc
diff --git a/content/browser/renderer_host/render_view_host_impl.cc b/content/browser/renderer_host/render_view_host_impl.cc
index bbf36ca52a50c95ed7bc6b1797c70265f498a210..efee671b22efa55ce7b8ed502c1ba1c37cf6e7ec 100644
--- a/content/browser/renderer_host/render_view_host_impl.cc
+++ b/content/browser/renderer_host/render_view_host_impl.cc
@@ -1719,6 +1719,7 @@ void RenderViewHostImpl::FilterURL(ChildProcessSecurityPolicyImpl* policy,
     // navigation to the home page. This is often a privileged page
     // (chrome://newtab/) which is exactly what we don't want.
     *url = GURL(chrome::kAboutBlankURL);
+    RecordAction(UserMetricsAction("FilterURLTermiate_Invalid"));
     return;
   }
 
@@ -1726,6 +1727,7 @@ void RenderViewHostImpl::FilterURL(ChildProcessSecurityPolicyImpl* policy,
     // The renderer treats all URLs in the about: scheme as being about:blank.
     // Canonicalize about: URLs to about:blank.
     *url = GURL(chrome::kAboutBlankURL);
+    RecordAction(UserMetricsAction("FilterURLTermiate_About"));
   }
 
   // Do not allow browser plugin guests to navigate to non-web URLs, since they
@@ -1739,6 +1741,7 @@ void RenderViewHostImpl::FilterURL(ChildProcessSecurityPolicyImpl* policy,
     // later.
     VLOG(1) << "Blocked URL " << url->spec();
     *url = GURL(chrome::kAboutBlankURL);
+    RecordAction(UserMetricsAction("FilterURLTermiate_Blocked"));
   }
 }