bfcache: Add test at the Chrome layer.

The back-forward cache is a content/ layer feature and it is tested on
this layer. For instance, this file contains a lot of tests:
content/browser/back_forward_cache_browsertest.cc

We also want to have some basic tests at the chrome layer to catch
trivial regressions. In particular, there is now an API available to
chrome/ to disable the BackForwardCache on arbitrary page. See:
https://docs.google.com/document/d/1NjZeusdS1kyEkZyfLggndU1A6qVt0Y1sa-LRUxnMoK8

Bug: 1010932
Change-Id: Ic0f0fc667f0d1de5157f95aea5f0558bc3d8557d
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/1836413Reviewed-by: Camille Lamy <clamy@chromium.org>
Reviewed-by: Colin Blundell <blundell@chromium.org>
Reviewed-by: Alexander Timin <altimin@chromium.org>
Commit-Queue: Arthur Sonzogni <arthursonzogni@chromium.org>
Cr-Commit-Position: refs/heads/master@{#703719}

chrome/browser/OWNERS

@@ -71,3 +71,8 @@ per-file web_bluetooth*=file://content/browser/bluetooth/OWNERS
 # For security review.
 per-file chrome_browser_interface_binders.cc=set noparent
 per-file chrome_browser_interface_binders.cc=file://ipc/SECURITY_OWNERS
+
+# BackForwardCache
+per-file chrome_back_forward_cache_browsertest.cc=arthursonzogni@chromium.org
+per-file chrome_back_forward_cache_browsertest.cc=altimin@chromium.org
+per-file chrome_back_forward_cache_browsertest.cc=file://content/OWNERS

chrome/browser/chrome_back_forward_cache_browsertest.cc

+// Copyright 2019 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 "base/macros.h"
+#include "base/test/scoped_feature_list.h"
+#include "chrome/browser/ui/browser.h"
+#include "chrome/browser/ui/tabs/tab_strip_model.h"
+#include "chrome/test/base/in_process_browser_test.h"
+#include "content/public/common/content_features.h"
+#include "content/public/test/browser_test_utils.h"
+#include "content/public/test/test_utils.h"
+#include "net/dns/mock_host_resolver.h"
+#include "net/test/embedded_test_server/embedded_test_server.h"
+
+class ChromeBackForwardCacheBrowserTest : public InProcessBrowserTest {
+ public:
+  ChromeBackForwardCacheBrowserTest() {
+    scoped_feature_list_.InitAndEnableFeatureWithParameters(
+        features::kBackForwardCache,
+        {
+            // Set a very long TTL before expiration (longer than the test
+            // timeout) so tests that are expecting deletion don't pass when
+            // they shouldn't.
+            {"TimeToLiveInBackForwardCacheInSeconds", "3600"},
+        });
+  }
+  ~ChromeBackForwardCacheBrowserTest() override {}
+
+  void SetUpOnMainThread() override {
+    host_resolver()->AddRule("*", "127.0.0.1");
+  }
+
+  // At the chrome layer, an outstanding request to /favicon.ico is made. It is
+  // made by the renderer on behalf of the browser process. It counts as an
+  // outstanding request, which prevents the page from entering the
+  // BackForwardCache, as long as it hasn't resolved.
+  //
+  // There are no real way to wait for this to complete. Not waiting would make
+  // the test potentially flaky. To prevent this, the no-favicon.html page is
+  // used, the image is not loaded from the network.
+  GURL GetURL(const std::string& host) {
+    return embedded_test_server()->GetURL(
+        host, "/back_forward_cache/no-favicon.html");
+  }
+
+ protected:
+  content::WebContents* web_contents() const {
+    return browser()->tab_strip_model()->GetActiveWebContents();
+  }
+
+  content::RenderFrameHost* current_frame_host() {
+    return web_contents()->GetMainFrame();
+  }
+
+ private:
+  base::test::ScopedFeatureList scoped_feature_list_;
+
+  DISALLOW_COPY_AND_ASSIGN(ChromeBackForwardCacheBrowserTest);
+};
+
+IN_PROC_BROWSER_TEST_F(ChromeBackForwardCacheBrowserTest, Basic) {
+  ASSERT_TRUE(embedded_test_server()->Start());
+
+  // 1) Navigate to A.
+  EXPECT_TRUE(content::NavigateToURL(web_contents(), GetURL("a.com")));
+  content::RenderFrameHost* rfh_a = current_frame_host();
+  content::RenderFrameDeletedObserver delete_observer_rfh_a(rfh_a);
+  EXPECT_TRUE(content::ExecJs(rfh_a, "token = 'rfh_a'"));
+
+  // 2) Navigate to B.
+  EXPECT_TRUE(content::NavigateToURL(web_contents(), GetURL("b.com")));
+  content::RenderFrameHost* rfh_b = current_frame_host();
+  content::RenderFrameDeletedObserver delete_observer_rfh_b(rfh_b);
+  EXPECT_TRUE(content::ExecJs(rfh_b, "token = 'rfh_b'"));
+
+  // A is frozen in the BackForwardCache.
+  EXPECT_FALSE(delete_observer_rfh_a.deleted());
+
+  // 3) Navigate back.
+  web_contents()->GetController().GoBack();
+  content::WaitForLoadStop(web_contents());
+
+  // A is restored, B is stored.
+  EXPECT_FALSE(delete_observer_rfh_a.deleted());
+  EXPECT_FALSE(delete_observer_rfh_b.deleted());
+
+  EXPECT_EQ("rfh_a", content::EvalJs(rfh_a, "token"));
+
+  // 4) Navigate forward.
+  web_contents()->GetController().GoForward();
+  content::WaitForLoadStop(web_contents());
+
+  // A is stored, B is restored.
+  EXPECT_FALSE(delete_observer_rfh_a.deleted());
+  EXPECT_FALSE(delete_observer_rfh_b.deleted());
+
+  EXPECT_EQ("rfh_b", content::EvalJs(rfh_b, "token"));
+}
+
+IN_PROC_BROWSER_TEST_F(ChromeBackForwardCacheBrowserTest, BasicIframe) {
+  ASSERT_TRUE(embedded_test_server()->Start());
+
+  // 1) Navigate to A.
+  EXPECT_TRUE(content::NavigateToURL(web_contents(), GetURL("a.com")));
+  content::RenderFrameHost* rfh_a = current_frame_host();
+  content::RenderFrameDeletedObserver delete_observer_rfh_a(rfh_a);
+  EXPECT_TRUE(content::ExecJs(rfh_a, "token = 'rfh_a'"));
+
+  // 2) Add an iframe B.
+  EXPECT_TRUE(content::ExecJs(rfh_a, R"(
+    let url = new URL(location.href);
+    url.hostname = 'b.com';
+    let iframe = document.createElement('iframe');
+    iframe.url = url;
+    document.body.appendChild(iframe);
+  )"));
+  content::WaitForLoadStop(web_contents());
+
+  content::RenderFrameHost* rfh_b = nullptr;
+  for (content::RenderFrameHost* rfh : web_contents()->GetAllFrames()) {
+    if (rfh != rfh_a)
+      rfh_b = rfh;
+  }
+  content::RenderFrameDeletedObserver delete_observer_rfh_b(rfh_b);
+
+  EXPECT_TRUE(content::ExecJs(rfh_a, "token = 'rfh_a'"));
+  EXPECT_TRUE(content::ExecJs(rfh_b, "token = 'rfh_b'"));
+
+  // 2) Navigate to C.
+  EXPECT_TRUE(content::NavigateToURL(web_contents(), GetURL("c.com")));
+
+  // A and B are frozen. The page A(B) is stored in the BackForwardCache.
+  EXPECT_FALSE(delete_observer_rfh_a.deleted());
+  EXPECT_FALSE(delete_observer_rfh_b.deleted());
+
+  // 3) Navigate back.
+  web_contents()->GetController().GoBack();
+  content::WaitForLoadStop(web_contents());
+
+  // The page A(B) is restored.
+  EXPECT_FALSE(delete_observer_rfh_a.deleted());
+  EXPECT_FALSE(delete_observer_rfh_b.deleted());
+  EXPECT_EQ("rfh_a", content::EvalJs(rfh_a, "token"));
+  EXPECT_EQ("rfh_b", content::EvalJs(rfh_b, "token"));
+}

chrome/test/BUILD.gn

@@ -845,6 +845,7 @@ if (!is_android) {
       "../browser/browsing_data/counters/passwords_counter_browsertest.cc",
       "../browser/browsing_data/counters/sync_aware_counter_browsertest.cc",
       "../browser/browsing_data/navigation_entry_remover_browsertest.cc",
+      "../browser/chrome_back_forward_cache_browsertest.cc",
       "../browser/chrome_content_browser_client_browsertest.cc",
       "../browser/chrome_do_not_track_browsertest.cc",
       "../browser/chrome_find_request_manager_browsertest.cc",

chrome/test/data/back_forward_cache/no-favicon.html

+<link rel="icon" href="data:,">