Revert of Keep track in the browser of which frames have onunload and onbeforeunload handlers.

content/browser/frame_host/navigation_request.cc

Index: content/browser/frame_host/navigation_request.cc
diff --git a/content/browser/frame_host/navigation_request.cc b/content/browser/frame_host/navigation_request.cc
index 6c343e60154f80e5b98e4d919150d79f18940337..ab3135bbc74f9df44173788376c21f34941c9e05 100644
--- a/content/browser/frame_host/navigation_request.cc
+++ b/content/browser/frame_host/navigation_request.cc
@@ -28,7 +28,6 @@
 #include "content/common/appcache_interfaces.h"
 #include "content/common/resource_request_body_impl.h"
 #include "content/public/browser/browser_context.h"
-#include "content/public/browser/browser_thread.h"
 #include "content/public/browser/content_browser_client.h"
 #include "content/public/browser/global_request_id.h"
 #include "content/public/browser/navigation_controller.h"
@@ -315,8 +314,7 @@ NavigationRequest::NavigationRequest(
       bindings_(NavigationEntryImpl::kInvalidBindings),
       response_should_be_rendered_(true),
       associated_site_instance_type_(AssociatedSiteInstanceType::NONE),
-      may_transfer_(may_transfer),
-      weak_factory_(this) {
+      may_transfer_(may_transfer) {
   DCHECK(!browser_initiated || (entry != nullptr && frame_entry != nullptr));
 
   // Sanitize the referrer.
@@ -668,19 +666,17 @@ void NavigationRequest::OnStartChecksComplete(
 
   // Abort the request if needed. This will destroy the NavigationRequest.
   if (result == NavigationThrottle::CANCEL_AND_IGNORE ||
-      result == NavigationThrottle::CANCEL ||
-      result == NavigationThrottle::BLOCK_REQUEST) {
+      result == NavigationThrottle::CANCEL) {
     // TODO(clamy): distinguish between CANCEL and CANCEL_AND_IGNORE.
-    int error_code = result == NavigationThrottle::BLOCK_REQUEST
-                         ? net::ERR_BLOCKED_BY_CLIENT
-                         : net::ERR_ABORTED;
-    // If the start checks completed synchronously, which could happen if there
-    // is no onbeforeunload handler, then this could cause reentrancy into
-    // NavigationController. So use a PostTask to avoid that.
-    BrowserThread::PostTask(
-        BrowserThread::UI, FROM_HERE,
-        base::Bind(&NavigationRequest::OnRequestFailed,
-                   weak_factory_.GetWeakPtr(), false, error_code));
+    OnRequestFailed(false, net::ERR_ABORTED);
+
+    // DO NOT ADD CODE after this. The previous call to OnRequestFailed has
+    // destroyed the NavigationRequest.
+    return;
+  }
+
+  if (result == NavigationThrottle::BLOCK_REQUEST) {
+    OnRequestFailed(false, net::ERR_BLOCKED_BY_CLIENT);
 
     // DO NOT ADD CODE after this. The previous call to OnRequestFailed has
     // destroyed the NavigationRequest.