android: Add a method to let Java know whether a prerender has finished loading.

chrome/browser/prerender/prerender_manager.h

Index: chrome/browser/prerender/prerender_manager.h
diff --git a/chrome/browser/prerender/prerender_manager.h b/chrome/browser/prerender/prerender_manager.h
index edec0f59963c136c3317c1ac0ce0b3526ee53b99..fdf874e3d3f8f5b0652c30b48241c0ba4c2f23fa 100644
--- a/chrome/browser/prerender/prerender_manager.h
+++ b/chrome/browser/prerender/prerender_manager.h
@@ -192,9 +192,16 @@ class PrerenderManager : public base::SupportsWeakPtr<PrerenderManager>,
                                  Origin* origin) const;
 
   // Whether the PrerenderManager has an active prerender with the given url and
-  // SessionStorageNamespace associated with the given WebContens.
+  // SessionStorageNamespace associated with the given WebContents.

[gavinp, 2016/02/25 18:44:55]

Thanks. This has bugged me for a while, but never had a change close enough.

   bool HasPrerenderedUrl(GURL url, content::WebContents* web_contents) const;
 
+  // Whether the PrerenderManager has an active prerender with the given url and
+  // SessionStorageNamespace associated with the given WebContents, and that
+  // prerender has finished loading..
+  bool HasPrerenderedAndFinishedLoadingUrl(
+      GURL url,
+      content::WebContents* web_contents) const;
+
   // Returns the PrerenderContents object for the given web_contents, otherwise
   // returns NULL. Note that the PrerenderContents may have been Destroy()ed,
   // but not yet deleted.