Suppress JavaScript dialogs when a tab puts itself into fullscreen.

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 6d104e2b0e36884ee371af60eeee487fb839eefe..4c8f9ff35448ef067589f8b64afb1430ac6000d7 100644
--- a/chrome/browser/prerender/prerender_contents.cc
+++ b/chrome/browser/prerender/prerender_contents.cc
@@ -147,7 +147,7 @@ class PrerenderContents::WebContentsDelegateImpl
     return false;
   }
 
-  bool ShouldSuppressDialogs(WebContents* source) override {
+  bool ShouldSuppressDialogs(WebContents* source, bool before_unload) 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);