Add instrumentation to see how often a local predictor prerender could be

chrome/browser/prerender/prerender_contents.cc

Index: chrome/browser/prerender/prerender_contents.cc
===================================================================
--- chrome/browser/prerender/prerender_contents.cc	(revision 199567)
+++ chrome/browser/prerender/prerender_contents.cc	(working copy)
@@ -538,7 +538,6 @@
 bool PrerenderContents::Matches(
     const GURL& url,
     const SessionStorageNamespace* session_storage_namespace) const {
-  DCHECK(child_id_ == -1 || session_storage_namespace);

[Shishir, 2013/05/14 20:01:43]

Why was this line written in the first place?

[tburkard, 2013/05/14 20:04:40]

Gavin had written this check based on the way it was used in the past, no
specific reason that this needs to be enforced/should be true.

   if (session_storage_namespace &&
       session_storage_namespace_id_ != session_storage_namespace->id()) {
     return false;