Add a browser test for the chrome://site-engagement WebUI.

chrome/browser/ui/webui/engagement/site_engagement_ui_browsertest.cc

+// Copyright 2017 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/engagement/site_engagement_service.h"
+#include "chrome/browser/ui/browser.h"
+#include "chrome/browser/ui/browser_commands.h"

[dominickn, 2017/03/30 06:05:24]

Not sure you need this one?

[Wez, 2017/03/31 05:21:04]

You're right, I think; I'd left this because of the Navigate... but that's the
ui_test_utils' version so we don't need this header as well.

+#include "chrome/browser/ui/tabs/tab_strip_model.h"
+#include "chrome/browser/ui/webui/chrome_web_ui_controller_factory.h"
+#include "chrome/common/url_constants.h"
+#include "chrome/test/base/in_process_browser_test.h"
+#include "chrome/test/base/ui_test_utils.h"
+#include "content/public/browser/child_process_security_policy.h"
+#include "content/public/browser/render_process_host.h"
+#include "content/public/common/content_switches.h"
+#include "content/public/test/browser_test_utils.h"
+
+namespace {
+
+const GURL kExampleUrl = GURL("https://www.example.com/");

[dominickn, 2017/03/30 06:05:24]

I'm surprised this doesn't fail some sort of static initialization check... can
you just inline it in the test body?

[Wez, 2017/03/31 05:21:02]

Static initializers are only checked on the perf bots, I think, and only for
production binaries, not tests, I think.

Rationale for putting it here was just that any tests added later should be able
to use the same constants, e.g. the cell name constants would live up here as
well.

+
+}  // namespace
+
+class SiteEngagementUiBrowserTest : public InProcessBrowserTest {
+ protected:
+  // Returns the SiteEngagementService for the test browser profile.
+  SiteEngagementService* engagement_service() {
+    return SiteEngagementService::Get(browser()->profile());
+  }
+
+  // (Re)sets the base score for a URL's site engagement.
+  void ResetBaseScore(GURL url, double score) {

[dominickn, 2017/03/30 06:05:24]

Nit: const GURL&

[Wez, 2017/03/31 05:21:03]

Done.

+    engagement_service()->ResetBaseScoreForURL(url, score);
+  }
+  void ResetBaseScoreToMax(GURL url) {

[dominickn, 2017/03/30 06:05:24]

Nit: const GURL&

[Wez, 2017/03/31 05:21:03]

Done.

+    ResetBaseScore(url, engagement_service()->GetMaxPoints());
+  }
+
+  // Navigates the tab to the site engagement WebUI.
+  void NavigateToWebUi() {
+    content::WebContents* web_contents =
+        browser()->tab_strip_model()->GetActiveWebContents();
+
+    const GURL web_ui_url(std::string(content::kChromeUIScheme) + "://" +
+                          std::string(chrome::kChromeUISiteEngagementHost));
+    EXPECT_TRUE(ChromeWebUIControllerFactory::GetInstance()->UseWebUIForURL(
+        web_contents->GetBrowserContext(), web_ui_url));
+    ui_test_utils::NavigateToURL(browser(), web_ui_url);
+    EXPECT_TRUE(
+        content::ChildProcessSecurityPolicy::GetInstance()->HasWebUIBindings(
+            web_contents->GetRenderProcessHost()->GetID()));
+
+    EXPECT_TRUE(content::WaitForLoadStop(web_contents));
+  }
+
+  // Waits for the tab to be populated with site engagement data.
+  void WaitUntilPagePopulated() {
+    ASSERT_TRUE(content::ExecuteScriptAndExtractBool(
+        browser()->tab_strip_model()->GetActiveWebContents(),
+        "window.setPagePopulatedCallbackForTest(function() {"
+        "  window.domAutomationController.send(true);"
+        "});",
+        &page_is_populated_));
+
+    ASSERT_TRUE(page_is_populated_);
+  }
+
+  // Verifies that a row exists for the specified site URL.
+  void ExpectPageContainsUrl(GURL url) {

[dominickn, 2017/03/30 06:05:24]

Nit: const GURL&

[Wez, 2017/03/31 05:21:02]

Done.

[Wez, 2017/03/31 05:21:03]

Done.

+    ASSERT_TRUE(page_is_populated_);
+
+    bool found_url = false;
+    ASSERT_TRUE(content::ExecuteScriptAndExtractBool(
+        browser()->tab_strip_model()->GetActiveWebContents(),
+        "var origin_cells = "
+        "    Array.from(document.getElementsByClassName('origin-cell'));"
+        "window.domAutomationController.send(origin_cells.reduce("
+        "    function(found, element) {"
+        "      return found || (element.innerHTML == '" +
+            url.spec() +
+            "');"
+            "    }, false));",
+        &found_url));
+    EXPECT_TRUE(found_url);
+  }
+
+ private:
+  // True if the page contains site engagement data.
+  bool page_is_populated_ = false;
+};
+
+IN_PROC_BROWSER_TEST_F(SiteEngagementUiBrowserTest, Basic) {
+  ResetBaseScoreToMax(kExampleUrl);
+
+  NavigateToWebUi();
+  WaitUntilPagePopulated();
+
+  ExpectPageContainsUrl(kExampleUrl);
+}