Add a way to cancel deferred navigations in NavigationHandle

content/public/browser/navigation_handle.h

Index: content/public/browser/navigation_handle.h
diff --git a/content/public/browser/navigation_handle.h b/content/public/browser/navigation_handle.h
index 3b2bbadda772a2f31a97b5faff489b0b730728c9..80ff291a9d5a9f5a65e7c423a8949b89ec407d20 100644
--- a/content/public/browser/navigation_handle.h
+++ b/content/public/browser/navigation_handle.h
@@ -93,6 +93,12 @@ class CONTENT_EXPORT NavigationHandle {
   // Resumes a navigation that was previously deferred by a NavigationThrottle.
   virtual void Resume() = 0;
 
+  // Cancels a navigation that was previously deferred by a NavigationThrottle.
+  // |result| should be equal to NavigationThrottle::CANCEL or
+  // NavigationThrottle::CANCEL_AND_IGNORE.
+  virtual void CancelDeferredNavigation(
+      NavigationThrottle::ThrottleCheckResult result) = 0;
+
   // Testing methods ----------------------------------------------------------
   //
   // The following methods should be used exclusively for writing unit tests.