Instant: Use only one hidden WebContents per profile.

chrome/browser/instant/instant_web_contents_container.cc

+// Copyright 2013 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/instant/instant_web_contents_container.h"
+
+#include "chrome/browser/extensions/api/web_navigation/web_navigation_api.h"
+#include "chrome/browser/favicon/favicon_tab_helper.h"
+#include "chrome/browser/safe_browsing/safe_browsing_tab_observer.h"
+#include "chrome/browser/ui/bookmarks/bookmark_tab_helper.h"
+#include "chrome/browser/ui/tab_contents/core_tab_helper.h"
+
+InstantWebContentsContainer::InstantWebContentsContainer(
+    InstantPage::Delegate* delegate,
+    InstantService* service)
+    : page_(delegate, service) {
+}
+
+InstantWebContentsContainer::~InstantWebContentsContainer() {
+}
+
+void InstantWebContentsContainer::SwapTabContents(
+    content::WebContents* old_contents,
+    content::WebContents* new_contents) {
+  DCHECK_EQ(contents_, old_contents);
+  TearDownContents();
+  // Release without deleting. Caller is supposed to delete |old_contents|.
+  ignore_result(contents_.release());
+  contents_.reset(new_contents);
+  SetUpContents();
+  page_.DetermineInstantSupport();
+}
+
+content::WebContents* InstantWebContentsContainer::OpenURLFromTab(
+    content::WebContents* /* source */,
+    const content::OpenURLParams& params) {
+  page_.set_supports_instant(false);
+
+  content::NavigationController::LoadURLParams load_params(params.url);
+  load_params.transition_type = params.transition;
+  load_params.referrer = params.referrer;
+  load_params.extra_headers = params.extra_headers;
+  load_params.is_renderer_initiated = params.is_renderer_initiated;
+  load_params.transferred_global_request_id =
+      params.transferred_global_request_id;
+  load_params.is_cross_site_redirect = params.is_cross_site_redirect;
+
+  contents_->GetController().LoadURLWithParams(load_params);
+  return contents();
+}
+
+bool InstantWebContentsContainer::ShouldFocusPageAfterCrash() {
+  return false;
+}
+
+bool InstantWebContentsContainer::CanDownload(
+    content::RenderViewHost* /* render_view_host */,
+    int /* request_id */,
+    const std::string& /* request_method */) {
+  return false;
+}
+
+bool InstantWebContentsContainer::OnGoToEntryOffset(int /* offset */) {
+  return false;
+}
+
+void InstantWebContentsContainer::SetUpContents() {
+  contents_->SetDelegate(this);
+  page_.SetContents(contents());
+  page_.set_supports_instant(false);
+
+  // Set up various tab helpers. The rest will get attached when (if) the
+  // contents is added to the tab strip.
+
+  // Bookmarks (Users can bookmark the Instant NTP. This ensures the bookmarked
+  // state is correctly set when the contents are swapped into a tab.)
+  BookmarkTabHelper::CreateForWebContents(contents());
+
+  // A tab helper to catch prerender content swapping shenanigans.
+  CoreTabHelper::CreateForWebContents(contents());
+  CoreTabHelper::FromWebContents(contents())->set_delegate(this);
+
+  // Observers.
+  extensions::WebNavigationTabObserver::CreateForWebContents(contents());
+
+  // Favicons, required by the Task Manager.
+  FaviconTabHelper::CreateForWebContents(contents());
+
+  // And some flat-out paranoia.
+  safe_browsing::SafeBrowsingTabObserver::CreateForWebContents(contents());
+}
+
+void InstantWebContentsContainer::TearDownContents() {
+  if (!contents_)
+    return;
+
+  contents_->SetDelegate(NULL);
+  page_.SetContents(NULL);
+  page_.set_supports_instant(false);
+
+  // Undo tab helper work done in SetUpContents().
+  CoreTabHelper::FromWebContents(contents())->set_delegate(NULL);
+}