Suppress JavaScript dialogs when a tab puts itself into fullscreen.

content/public/browser/web_contents_delegate.h

Index: content/public/browser/web_contents_delegate.h
diff --git a/content/public/browser/web_contents_delegate.h b/content/public/browser/web_contents_delegate.h
index 2816c4da06cf5e90a5c49238f7420f2b172d2db2..4d9009a71c2486e3c0a48ae959a160a9ea3cbbee 100644
--- a/content/public/browser/web_contents_delegate.h
+++ b/content/public/browser/web_contents_delegate.h
@@ -183,9 +183,10 @@ class CONTENT_EXPORT WebContentsDelegate {
   // Invoked prior to showing before unload handler confirmation dialog.
   virtual void WillRunBeforeUnloadConfirm() {}
 
-  // Returns true if javascript dialogs and unload alerts are suppressed.
-  // Default is false.
-  virtual bool ShouldSuppressDialogs(WebContents* source);
+  // Returns true if JavaScript dialogs and onbeforeunload requests are
+  // suppressed. |before_unload| is true if the dialog is an onbeforeunload
+  // request. The default is false, to not suppress dialogs.
+  virtual bool ShouldSuppressDialogs(WebContents* source, bool before_unload);
 
   // Returns whether pending NavigationEntries for aborted browser-initiated
   // navigations should be preserved (and thus returned from GetVisibleURL).