Add WebContents source to methods in WebContentsDelegate

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 c6489b618bb8e1014b9333c6172886bded53430e..4482cf96749e66e51604913dc133a68dbcecb70e 100644
--- a/chrome/browser/prerender/prerender_contents.cc
+++ b/chrome/browser/prerender/prerender_contents.cc
@@ -171,7 +171,7 @@ class PrerenderContents::WebContentsDelegateImpl
     return false;
   }
 
-  bool ShouldSuppressDialogs() override {
+  bool ShouldSuppressDialogs(WebContents* source) override {
     // We still want to show the user the message when they navigate to this
     // page, so cancel this prerender.
     prerender_contents_->Destroy(FINAL_STATUS_JAVASCRIPT_ALERT);