Shortcut cross-process frame transfers to avoid pending NavigationEntries.

chrome/browser/prerender/prerender_contents.cc

Index: chrome/browser/prerender/prerender_contents.cc
diff --git a/chrome/browser/prerender/prerender_contents.cc b/chrome/browser/prerender/prerender_contents.cc
index 2991013769160c746419f952aa4e60ae31b2f7c2..2b311ed4c0f934ac2700deb9a915ff93496022aa 100644
--- a/chrome/browser/prerender/prerender_contents.cc
+++ b/chrome/browser/prerender/prerender_contents.cc
@@ -92,15 +92,21 @@ class PrerenderContents::WebContentsDelegateImpl
                               const OpenURLParams& params) override {
     // |OpenURLFromTab| is typically called when a frame performs a navigation
     // that requires the browser to perform the transition instead of WebKit.
-    // Examples include prerendering a site that redirects to an app URL, or if
-    // --site-per-process is specified and the prerendered frame redirects to a
-    // different origin.
+    // Examples include client redirects to hosted app URLs.
     // TODO(cbentzel): Consider supporting this for CURRENT_TAB dispositions, if
     // it is a common case during prerenders.
     prerender_contents_->Destroy(FINAL_STATUS_OPEN_URL);
     return NULL;
   }
 
+  bool ShouldTransferNavigation() override {
+    // Cancel the prerender if the navigation attempts to transfer to a
+    // different process.  Examples include server redirects to privileged pages
+    // or cross-site subframe navigations in --site-per-process.
+    prerender_contents_->Destroy(FINAL_STATUS_OPEN_URL);
+    return false;
+  }
+
   void CloseContents(content::WebContents* contents) override {
     prerender_contents_->Destroy(FINAL_STATUS_CLOSED);
   }