Fixes for turning on offliner request.

chrome/browser/android/offline_pages/prerender_adapter.cc

 // Copyright 2016 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.
 
 #include "chrome/browser/android/offline_pages/prerender_adapter.h"
 
 #include "chrome/browser/prerender/prerender_manager.h"
 #include "chrome/browser/prerender/prerender_manager_factory.h"
 #include "chrome/browser/profiles/profile.h"
 #include "content/public/browser/browser_context.h"
@@ skipping 56 matching lines @@
   DCHECK(active_handle_->contents());
   return active_handle_->contents()->final_status();
 }
 
 bool PrerenderAdapter::IsActive() const {
   return active_handle_.get();
 }
 
 void PrerenderAdapter::DestroyActive() {
   DCHECK(IsActive());
-  active_handle_->OnCancel();
-  active_handle_.reset(nullptr);
+  // Clear active handle and call OnCancel from local variable to avoid
+  // immediate Observer OnPrerenderStop() call from thinking still active.
+  prerender::PrerenderHandle* handle_to_destroy = active_handle_.release();
+  handle_to_destroy->OnCancel();
+  delete handle_to_destroy;
 }
 
 void PrerenderAdapter::OnPrerenderStart(prerender::PrerenderHandle* handle) {
   DCHECK(active_handle_.get() == handle);
   observer_->OnPrerenderStart();
 }
 
 void PrerenderAdapter::OnPrerenderStopLoading(
     prerender::PrerenderHandle* handle) {
   DCHECK(active_handle_.get() == handle);
-  observer_->OnPrerenderDomContentLoaded();
+  observer_->OnPrerenderStopLoading();
 }
 
 void PrerenderAdapter::OnPrerenderDomContentLoaded(
     prerender::PrerenderHandle* handle) {
   DCHECK(active_handle_.get() == handle);
   observer_->OnPrerenderDomContentLoaded();
 }
 
 void PrerenderAdapter::OnPrerenderStop(prerender::PrerenderHandle* handle) {
-  DCHECK(active_handle_.get() == handle);
-  observer_->OnPrerenderStop();
+  if (IsActive()) {
+    DCHECK(active_handle_.get() == handle);
+    observer_->OnPrerenderStop();
+  }
 }
 
 }  // namespace offline_pages