PlzNavigate: Fix ordering of onBeforeNavigate and onCreatedNavigationTarget.

chrome/browser/extensions/api/web_navigation/web_navigation_api.cc

 // Copyright (c) 2012 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 // Implements the Chrome Extensions WebNavigation API.
 
 #include "chrome/browser/extensions/api/web_navigation/web_navigation_api.h"
 
 #include "base/lazy_instance.h"
 #include "chrome/browser/chrome_notification_types.h"
@@ skipping 253 matching lines @@
   navigation_state_.FrameHostCreated(new_host);
 }
 
 void WebNavigationTabObserver::DidStartNavigation(
     content::NavigationHandle* navigation_handle) {
   if (navigation_handle->IsSamePage() ||
       !FrameNavigationState::IsValidUrl(navigation_handle->GetURL())) {
     return;
   }
 
-  helpers::DispatchOnBeforeNavigate(navigation_handle);
+  pending_on_before_navigate_event_ =
+      helpers::CreateOnBeforeNavigateEvent(navigation_handle);
+
+  // Only dispatch the onBeforeNavigate event if the associated WebContents
+  // is already added to the tab strip. Otherwise the event should be delayed
+  // and sent after the addition, to preserve the ordering of events.
+  //
+  // TODO(nasko|devlin): This check is necessary because chrome::Navigate()
+  // begins the navigation before the sending the TAB_ADDED notification, and it
+  // is used an indication of that. It would be best if instead it was known
+  // when the tab was created and immediately sent the created event instead of
+  // waiting for the later TAB_ADDED notification, but this appears to work for
+  // now.
+  if (ExtensionTabUtil::GetTabById(ExtensionTabUtil::GetTabId(web_contents()),
+                                   web_contents()->GetBrowserContext(), false,
+                                   nullptr, nullptr, nullptr, nullptr)) {
+    DispatchCachedOnBeforeNavigate();
+  }
 }
 
 void WebNavigationTabObserver::DidFinishNavigation(
     content::NavigationHandle* navigation_handle) {
+  // If there has been a DidStartNavigation call before the tab was ready to
+  // dispatch events, ensure that it is sent before processing the
+  // DidFinishNavigation.
+  // Note: This is exercised by WebNavigationApiTest.TargetBlankIncognito.
+  DispatchCachedOnBeforeNavigate();
+
   if (navigation_handle->HasCommitted() && !navigation_handle->IsErrorPage()) {
     HandleCommit(navigation_handle);
     return;
   }
 
   HandleError(navigation_handle);
 }
 
 void WebNavigationTabObserver::DocumentLoadedInFrame(
     content::RenderFrameHost* render_frame_host) {
@@ skipping 95 matching lines @@
                                              source_render_frame_host,
                                              new_contents,
                                              url);
 }
 
 void WebNavigationTabObserver::WebContentsDestroyed() {
   g_tab_observer.Get().erase(web_contents());
   registrar_.RemoveAll();
 }
 
+void WebNavigationTabObserver::DispatchCachedOnBeforeNavigate() {
+  if (!pending_on_before_navigate_event_)
+    return;
+
+  // EventRouter can be null in unit tests.
+  EventRouter* event_router =
+      EventRouter::Get(web_contents()->GetBrowserContext());
+  if (event_router)
+    event_router->BroadcastEvent(std::move(pending_on_before_navigate_event_));
+}
+
 void WebNavigationTabObserver::HandleCommit(
     content::NavigationHandle* navigation_handle) {
   bool is_reference_fragment_navigation = IsReferenceFragmentNavigation(
       navigation_handle->GetRenderFrameHost(), navigation_handle->GetURL());
 
   navigation_state_.StartTrackingDocumentLoad(
       navigation_handle->GetRenderFrameHost(), navigation_handle->GetURL(),
       navigation_handle->IsSamePage(),
       false,  // is_error_page
       navigation_handle->IsSrcdoc());
@@ skipping 156 matching lines @@
   return g_factory.Pointer();
 }
 
 void WebNavigationAPI::OnListenerAdded(const EventListenerInfo& details) {
   web_navigation_event_router_.reset(new WebNavigationEventRouter(
       Profile::FromBrowserContext(browser_context_)));
   EventRouter::Get(browser_context_)->UnregisterObserver(this);
 }
 
 }  // namespace extensions