Don't assume WebContents has a LastCommittedEntry when setting zoom.

content/browser/host_zoom_map_impl.cc

Index: content/browser/host_zoom_map_impl.cc
diff --git a/content/browser/host_zoom_map_impl.cc b/content/browser/host_zoom_map_impl.cc
index a0a68dad95a2c860e42b0bb9dc3f519882a6a8b2..634771a1089ef8a54fd7d79c56c19656fb07744f 100644
--- a/content/browser/host_zoom_map_impl.cc
+++ b/content/browser/host_zoom_map_impl.cc
@@ -250,9 +250,10 @@ void HostZoomMapImpl::SetZoomLevelForWebContents(
     GURL url;
     NavigationEntry* entry =
         web_contents_impl.GetController().GetLastCommittedEntry();
-    DCHECK(entry);
-    url = entry->GetURL();
-    SetZoomLevelForHost(net::GetHostOrSpecFromURL(url), level);
+    if (entry) {

[Peter Kasting, 2014/06/09 18:17:57]

Nit: Add a comment about why this can be NULL.  Ideally, the comments both here
and above actually give the reader some detail about the codepath that leads to
this, rather than just saying something like "it's possible there is no entry
yet".

+      url = entry->GetURL();

[wjmaclean, 2014/06/09 17:35:59]

Actually, this should be 

GURL url = ...

No need to declare it outside the if()

+      SetZoomLevelForHost(net::GetHostOrSpecFromURL(url), level);
+    }
   }
 }