PrerenderingLoader initial integration with PrerenderManager/PrerenderHandle

chrome/browser/android/offline_pages/prerender_adapter.cc

Index: chrome/browser/android/offline_pages/prerender_adapter.cc
diff --git a/chrome/browser/android/offline_pages/prerender_adapter.cc b/chrome/browser/android/offline_pages/prerender_adapter.cc
new file mode 100644
index 0000000000000000000000000000000000000000..17b8bf0251dd59b1edc875262199a97a32c660c7
--- /dev/null
+++ b/chrome/browser/android/offline_pages/prerender_adapter.cc
@@ -0,0 +1,87 @@
+// 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 "base/location.h"
+#include "base/logging.h"
+#include "chrome/browser/android/offline_pages/prerendering_loader.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"
+#include "content/public/browser/web_contents.h"
+#include "ui/gfx/geometry/size.h"
+
+namespace offline_pages {
+
+PrerenderAdapter::PrerenderAdapter() {}
+PrerenderAdapter::~PrerenderAdapter() {}

[pasko, 2016/05/17 15:34:20]

nit: empty line above

+
+bool PrerenderAdapter::CanPrerender() const {
+  return prerender::PrerenderManager::ActuallyPrerendering();
+}
+
+bool PrerenderAdapter::AddPrerenderForOffline(
+    content::BrowserContext* browser_context,
+    const GURL& url,
+    content::SessionStorageNamespace* session_storage_namespace,
+    const gfx::Size& size) {
+  DCHECK(!IsActive());
+  Profile* profile = Profile::FromBrowserContext(browser_context);
+  prerender::PrerenderManager* manager =
+      prerender::PrerenderManagerFactory::GetForProfile(profile);
+  DCHECK(manager);
+  // Start prerendering the url and capture the handle for the prerendering.
+  active_handle_.reset(
+      manager->AddPrerenderForOffline(url, session_storage_namespace, size));
+  return active_handle_.get();
+}
+
+void PrerenderAdapter::SetObserver(
+    prerender::PrerenderHandle::Observer* observer) {
+  DCHECK(IsActive());
+  active_handle_->SetObserver(observer);
+}
+
+bool PrerenderAdapter::IsPrerendering() const {
+  DCHECK(IsActive());
+  return active_handle_->IsPrerendering();
+}
+
+void PrerenderAdapter::OnCancel() {
+  DCHECK(IsActive());
+  active_handle_->OnCancel();
+}
+
+content::WebContents* PrerenderAdapter::GetWebContents() const {
+  DCHECK(IsActive());
+  if (active_handle_->contents()) {
+    // Note: the prerender stack maintains ownership of these contents
+    // and PrerenderingLoader::StopLoading() must be called to report
+    // the Loader is done with the contents.
+    return active_handle_->contents()->prerender_contents();
+  }
+  return nullptr;
+}
+
+prerender::FinalStatus PrerenderAdapter::GetFinalStatus() const {
+  DCHECK(IsActive());
+  DCHECK(active_handle_->contents());
+  return active_handle_->contents()->final_status();
+}
+
+bool PrerenderAdapter::IsActive() const {
+  return active_handle_.get();
+}
+
+bool PrerenderAdapter::IsActive(prerender::PrerenderHandle* handle) const {
+  return active_handle_.get() == handle;
+}
+
+void PrerenderAdapter::DestroyActive() {
+  active_handle_.reset(nullptr);

[pasko, 2016/05/12 19:10:07]

PrerenderHandle destructor has this comment:
  // Before calling the destructor, the caller must invalidate the handle by
  // calling either OnNavigateAway or OnCancel.

We should either provide a similar comment for the adapter or move the OnCancel
body here. I would prefer the latter as less error prone.

[dougarnett, 2016/05/13 00:00:24]

Done.

+}
+
+}  // namespace offline_pages