Cleanup: Modernizes some parts of CrossPlatformAccessibilityBrowserTest,...

Cleanup: Modernizes some parts of CrossPlatformAccessibilityBrowserTest, enables all disabled tests and makes them more consistent with other accessibility browser tests

Some tests having to do with iframe traversal in CrossPlatformAccessibilityBrowserTest were disabled.
In https://crrev.com/c/2556452, the kPDFRoot role is being added and the kWebArea role is being removed.
Iframe traversal tests should be enabled and functioning to ensure the robustness of any code changes
in those roles, as they could potentially break iframe navigation.

Meanwhile, many of the code convensions used in CrossPlatformAccessibilityBrowserTest were different from all other accessibility browser tests
and some have been superceded by changes to C++.

This patch switches to using raw literal strings for loading HTML snippets, improves indentation, and
uses the same method names for loading test pages as in other accessibility browser tests.
Also, useless comments were eliminated and test fixtures cleaned up were necessary.

Originally split out from
https://crrev.com/c/2556452

AX-Relnotes: n/a.

R=dmazzoni@chromium.org, aleventhal@chromium.org

Change-Id: Ia9c3094606581468d7f1b5c8849bb44668b47de1
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2575101
Commit-Queue: Nektarios Paisios <nektar@chromium.org>
Auto-Submit: Nektarios Paisios <nektar@chromium.org>
Reviewed-by: Abigail Klein <abigailbklein@google.com>
Cr-Commit-Position: refs/heads/master@{#836225}

content/browser/accessibility/cross_platform_accessibility_browsertest.cc

@@ -28,12 +28,14 @@
 #include "content/public/test/content_browser_test.h"
 #include "content/public/test/content_browser_test_utils.h"
 #include "content/shell/browser/shell.h"
+#include "net/base/escape.h"
 #include "testing/gmock/include/gmock/gmock.h"
 #include "third_party/blink/public/common/features.h"
 #include "ui/accessibility/accessibility_features.h"
 #include "ui/accessibility/accessibility_switches.h"
 #include "ui/accessibility/ax_node.h"
 #include "ui/accessibility/ax_tree.h"
+#include "ui/accessibility/ax_tree_id.h"
 
 #if defined(OS_WIN)
 #include "base/win/atl.h"
@@ -56,22 +58,12 @@ namespace content {
 
 class CrossPlatformAccessibilityBrowserTest : public ContentBrowserTest {
  public:
-  CrossPlatformAccessibilityBrowserTest() {}
-
-  // Tell the renderer to send an accessibility tree, then wait for the
-  // notification that it's been received.
-  const ui::AXTree& GetAXTree(
-      ui::AXMode accessibility_mode = ui::kAXModeComplete) {
-    AccessibilityNotificationWaiter waiter(shell()->web_contents(),
-                                           accessibility_mode,
-                                           ax::mojom::Event::kLayoutComplete);
-    waiter.WaitForNotification();
-    return waiter.GetAXTree();
-  }
+  CrossPlatformAccessibilityBrowserTest() = default;
+  ~CrossPlatformAccessibilityBrowserTest() override = default;
 
   // Make sure each node in the tree has a unique id.
   void RecursiveAssertUniqueIds(const ui::AXNode* node,
-                                std::unordered_set<int>* ids) {
+                                std::unordered_set<int>* ids) const {
     ASSERT_TRUE(ids->find(node->id()) == ids->end());
     ids->insert(node->id());
     for (const auto* child : node->children())
@@ -80,7 +72,6 @@ class CrossPlatformAccessibilityBrowserTest : public ContentBrowserTest {
 
   void SetUp() override;
   void SetUpOnMainThread() override;
-  void TearDownOnMainThread() override;
 
   void SetUpCommandLine(base::CommandLine* command_line) override {
     ContentBrowserTest::SetUpCommandLine(command_line);
@@ -100,32 +91,41 @@ class CrossPlatformAccessibilityBrowserTest : public ContentBrowserTest {
         base::ASCIIToUTF16(script), base::NullCallback());
   }
 
-  void LoadInitialAccessibilityTreeFromUrl(
-      const GURL& url,
-      ui::AXMode accessibility_mode = ui::kAXModeComplete) {
+  void LoadInitialAccessibilityTreeFromHtml(const std::string& html) {
     AccessibilityNotificationWaiter waiter(shell()->web_contents(),
-                                           accessibility_mode,
+                                           ui::kAXModeComplete,
                                            ax::mojom::Event::kLoadComplete);
-    EXPECT_TRUE(NavigateToURL(shell(), url));
+    GURL html_data_url(
+        net::EscapeExternalHandlerValue("data:text/html," + html));
+    ASSERT_TRUE(NavigateToURL(shell(), html_data_url));
     waiter.WaitForNotification();
   }
 
   void LoadInitialAccessibilityTreeFromHtmlFilePath(
-      const std::string& html_file_path,
-      ui::AXMode accessibility_mode = ui::kAXModeComplete) {
+      const std::string& html_file_path) {
     if (!embedded_test_server()->Started())
       ASSERT_TRUE(embedded_test_server()->Start());
     ASSERT_TRUE(embedded_test_server()->Started());
-    LoadInitialAccessibilityTreeFromUrl(
-        embedded_test_server()->GetURL(html_file_path), accessibility_mode);
+    AccessibilityNotificationWaiter waiter(shell()->web_contents(),
+                                           ui::kAXModeComplete,
+                                           ax::mojom::Event::kLoadComplete);
+    ASSERT_TRUE(
+        NavigateToURL(shell(), embedded_test_server()->GetURL(html_file_path)));
+    waiter.WaitForNotification();
   }
 
-  BrowserAccessibilityManager* GetManager() {
+  BrowserAccessibilityManager* GetManager() const {
     WebContentsImpl* web_contents =
         static_cast<WebContentsImpl*>(shell()->web_contents());
     return web_contents->GetRootBrowserAccessibilityManager();
   }
 
+  const ui::AXTree& GetAXTree() const {
+    const ui::AXTree* ax_tree = GetManager()->ax_tree();
+    EXPECT_NE(nullptr, ax_tree);
+    return *ax_tree;
+  }
+
   BrowserAccessibility* FindNode(const std::string& name_or_value) {
     return FindNodeInSubtree(*GetManager()->GetRoot(), name_or_value);
   }
@@ -142,7 +142,7 @@ class CrossPlatformAccessibilityBrowserTest : public ContentBrowserTest {
     // Will expose no HTML value attribute, but some screen readers, such as
     // Jaws, VoiceOver and Talkback, require one to be computed.
     const std::string& value = base::UTF16ToUTF8(node.GetValueForControl());
-    if ((name == name_or_value || value == name_or_value)) {
+    if (name == name_or_value || value == name_or_value) {
       return &node;
     }
 
@@ -195,14 +195,8 @@ void CrossPlatformAccessibilityBrowserTest::ChooseFeatures(
 
 void CrossPlatformAccessibilityBrowserTest::SetUpOnMainThread() {
 #if defined(OS_WIN)
+  com_initializer_ = std::make_unique<base::win::ScopedCOMInitializer>();
   ui::win::CreateATLModuleIfNeeded();
-  com_initializer_.reset(new base::win::ScopedCOMInitializer());
-#endif
-}
-
-void CrossPlatformAccessibilityBrowserTest::TearDownOnMainThread() {
-#if defined(OS_WIN)
-  com_initializer_.reset();
 #endif
 }
 
@@ -265,20 +259,25 @@ BrowserAccessibility* FindNodeByRole(BrowserAccessibility* root,
 
 IN_PROC_BROWSER_TEST_F(CrossPlatformAccessibilityBrowserTest,
                        WebpageAccessibility) {
-  // Create a data url and load it.
-  const char url_str[] =
-      "data:text/html,"
-      "<!doctype html>"
-      "<html><head><title>Accessibility Test</title></head>"
-      "<body><input type='button' value='push' /><input type='checkbox' />"
-      "</body></html>";
-  GURL url(url_str);
-  EXPECT_TRUE(NavigateToURL(shell(), url));
+  const std::string url_str(R"HTML(
+      <!DOCTYPE html>
+      <html>
+      <head>
+        <title>Accessibility Test</title>
+      </head>
+      <body>
+        <input type="button" value="push">
+        <input type="checkbox">
+      </body>
+      </html>)HTML");
+  LoadInitialAccessibilityTreeFromHtml(url_str);
+
   const ui::AXTree& tree = GetAXTree();
   const ui::AXNode* root = tree.root();
 
-  // Check properties of thet tree.
-  EXPECT_EQ(url_str, tree.data().url);
+  // Check properties of the tree.
+  EXPECT_EQ(net::EscapeExternalHandlerValue("data:text/html," + url_str),
+            tree.data().url);
   EXPECT_EQ("Accessibility Test", tree.data().title);
   EXPECT_EQ("html", tree.data().doctype);
   EXPECT_EQ("text/html", tree.data().mimetype);
@@ -318,15 +317,13 @@ IN_PROC_BROWSER_TEST_F(CrossPlatformAccessibilityBrowserTest,
 
 IN_PROC_BROWSER_TEST_F(CrossPlatformAccessibilityBrowserTest,
                        UnselectedEditableTextAccessibility) {
-  // Create a data url and load it.
-  const char url_str[] =
-      "data:text/html,"
-      "<!doctype html>"
-      "<body>"
-      "<input value=\"Hello, world.\"/>"
-      "</body></html>";
-  GURL url(url_str);
-  EXPECT_TRUE(NavigateToURL(shell(), url));
+  LoadInitialAccessibilityTreeFromHtml(R"HTML(
+      <!DOCTYPE html>
+      <html>
+      <body>
+        <input value="Hello, world.">
+      </body>
+      </html>)HTML");
 
   const ui::AXTree& tree = GetAXTree();
   const ui::AXNode* root = tree.root();
@@ -348,15 +345,13 @@ IN_PROC_BROWSER_TEST_F(CrossPlatformAccessibilityBrowserTest,
 
 IN_PROC_BROWSER_TEST_F(CrossPlatformAccessibilityBrowserTest,
                        SelectedEditableTextAccessibility) {
-  // Create a data url and load it.
-  const char url_str[] =
-      "data:text/html,"
-      "<!doctype html>"
-      "<body onload=\"document.body.children[0].select();\">"
-      "<input value=\"Hello, world.\"/>"
-      "</body></html>";
-  GURL url(url_str);
-  EXPECT_TRUE(NavigateToURL(shell(), url));
+  LoadInitialAccessibilityTreeFromHtml(R"HTML(
+      <!DOCTYPE html>
+      <html>
+      <body onload="document.body.children[0].select();">
+        <input value="Hello, world.">
+      </body>
+      </html>)HTML");
 
   const ui::AXTree& tree = GetAXTree();
   const ui::AXNode* root = tree.root();
@@ -377,17 +372,16 @@ IN_PROC_BROWSER_TEST_F(CrossPlatformAccessibilityBrowserTest,
   // Here's a html snippet where Blink puts the same node as a child
   // of two different parents. Instead of checking the exact output, just
   // make sure that no id is reused in the resulting tree.
-  const char url_str[] =
-      "data:text/html,"
-      "<!doctype html>"
-      "<script>\n"
-      "  document.writeln('<q><section></section></q><q><li>');\n"
-      "  setTimeout(function() {\n"
-      "    document.close();\n"
-      "  }, 1);\n"
-      "</script>";
-  GURL url(url_str);
-  EXPECT_TRUE(NavigateToURL(shell(), url));
+  LoadInitialAccessibilityTreeFromHtml(R"HTML(
+      <!DOCTYPE html>
+      <html>
+        <script>
+          document.writeln('<q><section></section></q><q><li>');
+          setTimeout(function() {
+            document.close();
+          }, 1);
+        </script>
+      </html>)HTML");
 
   const ui::AXTree& tree = GetAXTree();
   const ui::AXNode* root = tree.root();
@@ -395,26 +389,36 @@ IN_PROC_BROWSER_TEST_F(CrossPlatformAccessibilityBrowserTest,
   RecursiveAssertUniqueIds(root, &ids);
 }
 
-// TODO(dmazzoni): Needs to be rebaselined. http://crbug.com/347464
 IN_PROC_BROWSER_TEST_F(CrossPlatformAccessibilityBrowserTest,
-                       DISABLED_IframeAccessibility) {
-  // Create a data url and load it.
-  const char url_str[] =
-      "data:text/html,"
-      "<!doctype html><html><body>"
-      "<button>Button 1</button>"
-      "<iframe src='data:text/html,"
-      "<!doctype html><html><body><button>Button 2</button></body></html>"
-      "'></iframe>"
-      "<button>Button 3</button>"
-      "</body></html>";
-  GURL url(url_str);
-  EXPECT_TRUE(NavigateToURL(shell(), url));
+                       IframeAccessibility) {
+  LoadInitialAccessibilityTreeFromHtml(R"HTML(
+      <!DOCTYPE html>
+      <html>
+      <body>
+        <button>Button 1</button>
+        <iframe srcdoc="
+          <!DOCTYPE html>
+          <html>
+          <body>
+            <button>Button 2</button>
+          </body>
+          </html>
+        "></iframe>
+        <button>Button 3</button>
+      </body>
+      </html>)HTML");
+
+  WaitForAccessibilityTreeToContainNodeWithName(shell()->web_contents(),
+                                                "Button 2");
 
   const ui::AXTree& tree = GetAXTree();
   const ui::AXNode* root = tree.root();
-  ASSERT_EQ(1u, root->GetUnignoredChildCount());
-  const ui::AXNode* body = root->GetUnignoredChildAtIndex(0);
+  ASSERT_EQ(1u, root->children().size());
+
+  const ui::AXNode* html_element = root->children()[0];
+  ASSERT_EQ(1u, html_element->GetUnignoredChildCount());
+
+  const ui::AXNode* body = html_element->children()[0];
   ASSERT_EQ(3u, body->GetUnignoredChildCount());
 
   const ui::AXNode* button1 = body->GetUnignoredChildAtIndex(0);
@@ -425,13 +429,26 @@ IN_PROC_BROWSER_TEST_F(CrossPlatformAccessibilityBrowserTest,
   const ui::AXNode* iframe = body->GetUnignoredChildAtIndex(1);
   EXPECT_STREQ("iframe",
                GetAttr(iframe, ax::mojom::StringAttribute::kHtmlTag).c_str());
-  ASSERT_EQ(1u, iframe->GetUnignoredChildCount());
 
-  const ui::AXNode* sub_document = iframe->GetUnignoredChildAtIndex(0);
+  // Iframes loaded via the "srcdoc" attribute, (or the now deprecated method of
+  // "src=data:text/html,..."), create a new origin context and are thus loaded
+  // into a separate accessibility tree. (See "out-of-process cross-origin
+  // iframes in Chromium documentation.)
+  ASSERT_EQ(0u, iframe->children().size());
+  const ui::AXTreeID iframe_tree_id = AXTreeID::FromString(
+      GetAttr(iframe, ax::mojom::StringAttribute::kChildTreeId));
+  const BrowserAccessibilityManager* iframe_manager =
+      BrowserAccessibilityManager::FromID(iframe_tree_id);
+  ASSERT_NE(nullptr, iframe_manager);
+
+  const ui::AXNode* sub_document = iframe_manager->GetRootAsAXNode();
   EXPECT_EQ(ax::mojom::Role::kRootWebArea, sub_document->data().role);
-  ASSERT_EQ(1u, sub_document->GetUnignoredChildCount());
+  ASSERT_EQ(1u, sub_document->children().size());
+
+  const ui::AXNode* sub_html_element = sub_document->children()[0];
+  ASSERT_EQ(1u, sub_html_element->GetUnignoredChildCount());
 
-  const ui::AXNode* sub_body = sub_document->GetUnignoredChildAtIndex(0);
+  const ui::AXNode* sub_body = sub_html_element->children()[0];
   ASSERT_EQ(1u, sub_body->GetUnignoredChildCount());
 
   const ui::AXNode* button2 = sub_body->GetUnignoredChildAtIndex(0);
@@ -447,22 +464,23 @@ IN_PROC_BROWSER_TEST_F(CrossPlatformAccessibilityBrowserTest,
 
 IN_PROC_BROWSER_TEST_F(CrossPlatformAccessibilityBrowserTest,
                        PlatformIframeAccessibility) {
-  AccessibilityNotificationWaiter waiter(shell()->web_contents(),
-                                         ui::kAXModeComplete,
-                                         ax::mojom::Event::kLoadComplete);
-  // Create a data url and load it.
-  GURL url(
-      "data:text/html,"
-      "<!doctype html><html><body>"
-      "<button>Button 1</button>"
-      "<iframe src='data:text/html,"
-      "<!doctype html><html><body><button>Button 2</button></body></html>"
-      "'></iframe>"
-      "<button>Button 3</button>"
-      "</body></html>");
-
-  EXPECT_TRUE(NavigateToURL(shell(), url));
-  waiter.WaitForNotification();
+  LoadInitialAccessibilityTreeFromHtml(R"HTML(
+      <!DOCTYPE html>
+      <html>
+      <body>
+        <button>Button 1</button>
+        <iframe srcdoc="
+          <!DOCTYPE html>
+          <html>
+          <body>
+            <button>Button 2</button>
+          </body>
+          </html>
+        "></iframe>
+        <button>Button 3</button>
+      </body>
+      </html>)HTML");
+
   WaitForAccessibilityTreeToContainNodeWithName(shell()->web_contents(),
                                                 "Button 2");
 
@@ -507,21 +525,18 @@ IN_PROC_BROWSER_TEST_F(CrossPlatformAccessibilityBrowserTest,
 #if !defined(OS_ANDROID)
 IN_PROC_BROWSER_TEST_F(CrossPlatformAccessibilityBrowserTest,
                        AXNodePositionTreeBoundary) {
-  AccessibilityNotificationWaiter waiter(shell()->web_contents(),
-                                         ui::kAXModeComplete,
-                                         ax::mojom::Event::kLoadComplete);
-  GURL url(
-      "data:text/html,"
-      "<!doctype html><html><body>"
-      "Text before iframe"
-      "<iframe src='data:text/html,"
-      "<!doctype html><html><body>Text in iframe</body></html>"
-      "'></iframe>"
-      "Text after iframe"
-      "</body></html>");
-
-  EXPECT_TRUE(NavigateToURL(shell(), url));
-  waiter.WaitForNotification();
+  LoadInitialAccessibilityTreeFromHtml(R"HTML(
+      <!DOCTYPE html>
+      <html>
+      <body>Text before iframe<iframe srcdoc="
+          <!DOCTYPE html>
+          <html>
+          <body>Text in iframe
+          </body>
+          </html>">
+        </iframe>Text after iframe</body>
+      </html>)HTML");
+
   WaitForAccessibilityTreeToContainNodeWithName(shell()->web_contents(),
                                                 "Text in iframe");
 
@@ -602,24 +617,24 @@ IN_PROC_BROWSER_TEST_F(CrossPlatformAccessibilityBrowserTest,
 
 IN_PROC_BROWSER_TEST_F(CrossPlatformAccessibilityBrowserTest,
                        PlatformIterator) {
-  AccessibilityNotificationWaiter waiter(shell()->web_contents(),
-                                         ui::kAXModeComplete,
-                                         ax::mojom::Event::kLoadComplete);
-  // Create a data url and load it.
-  GURL url(
-      "data:text/html,"
-      "<!doctype html><html><body>"
-      "<button>Button 1</button>"
-      "<iframe src='data:text/html,"
-      "<!doctype html><html><body>"
-      "<button>Button 2</button>"
-      "<button>Button 3</button>"
-      "</body></html>'></iframe>"
-      "<button>Button 4</button>"
-      "</body></html>");
-
-  EXPECT_TRUE(NavigateToURL(shell(), url));
-  waiter.WaitForNotification();
+  LoadInitialAccessibilityTreeFromHtml(R"HTML(
+      <!DOCTYPE html>
+      <html>
+      <body>
+        <button>Button 1</button>
+        <iframe srcdoc="
+          <!DOCTYPE html>
+          <html>
+          <body>
+            <button>Button 2</button>
+            <button>Button 3</button>
+          </body>
+          </html>">
+        </iframe>
+        <button>Button 4</button>
+      </body>
+      </html>)HTML");
+
   WaitForAccessibilityTreeToContainNodeWithName(shell()->web_contents(),
                                                 "Button 2");
   const BrowserAccessibility* root = GetManager()->GetRoot();
@@ -659,12 +674,16 @@ IN_PROC_BROWSER_TEST_F(CrossPlatformAccessibilityBrowserTest,
   // Here's another html snippet where WebKit has a parent node containing
   // two duplicate child nodes. Instead of checking the exact output, just
   // make sure that no id is reused in the resulting tree.
-  const char url_str[] =
-      "data:text/html,"
-      "<!doctype html>"
-      "<em><code ><h4 ></em>";
-  GURL url(url_str);
-  EXPECT_TRUE(NavigateToURL(shell(), url));
+  LoadInitialAccessibilityTreeFromHtml(R"HTML(
+      <!DOCTYPE html>
+      <html>
+      <body>
+        <em>
+          <code >
+            <h4 >
+        </em>
+      </body>
+      </html>)HTML");
 
   const ui::AXTree& tree = GetAXTree();
   const ui::AXNode* root = tree.root();
@@ -673,14 +692,16 @@ IN_PROC_BROWSER_TEST_F(CrossPlatformAccessibilityBrowserTest,
 }
 
 IN_PROC_BROWSER_TEST_F(CrossPlatformAccessibilityBrowserTest, WritableElement) {
-  const char url_str[] =
-      "data:text/html,"
-      "<!doctype html>"
-      "<div role='textbox' tabindex=0>"
-      " Some text"
-      "</div>";
-  GURL url(url_str);
-  EXPECT_TRUE(NavigateToURL(shell(), url));
+  LoadInitialAccessibilityTreeFromHtml(R"HTML(
+      <!DOCTYPE html>
+      <html>
+      <body>
+        <div role="textbox" tabindex="0">
+          Some text
+        </div>
+      </body>
+      </html>)HTML");
+
   const ui::AXTree& tree = GetAXTree();
   const ui::AXNode* root = tree.root();
   ASSERT_EQ(1u, root->GetUnignoredChildCount());
@@ -690,18 +711,21 @@ IN_PROC_BROWSER_TEST_F(CrossPlatformAccessibilityBrowserTest, WritableElement) {
 
 IN_PROC_BROWSER_TEST_F(CrossPlatformAccessibilityBrowserTest,
                        AriaSortDirection) {
-  const char url_str[] =
-      "data:text/html,"
-      "<!doctype html>"
-      "<table><tr>"
-      "<th scope='row' aria-sort='ascending'>row header 1</th>"
-      "<th scope='row' aria-sort='descending'>row header 2</th>"
-      "<th scope='col' aria-sort='custom'>col header 1</th>"
-      "<th scope='col' aria-sort='none'>col header 2</th>"
-      "<th scope='col'>col header 3</th>"
-      "</tr></table>";
-  GURL url(url_str);
-  EXPECT_TRUE(NavigateToURL(shell(), url));
+  LoadInitialAccessibilityTreeFromHtml(R"HTML(
+      <!DOCTYPE html>
+      <html>
+      <body>
+        <table>
+          <tr>
+            <th scope="row" aria-sort="ascending">row header 1</th>
+            <th scope="row" aria-sort="descending">row header 2</th>
+            <th scope="col" aria-sort="custom">col header 1</th>
+            <th scope="col" aria-sort="none">col header 2</th>
+            <th scope="col">col header 3</th>
+          </tr>
+        </table>
+      </body>
+      </html>)HTML");
 
   const ui::AXTree& tree = GetAXTree();
   const ui::AXNode* root = tree.root();
@@ -732,32 +756,29 @@ IN_PROC_BROWSER_TEST_F(CrossPlatformAccessibilityBrowserTest,
 
 IN_PROC_BROWSER_TEST_F(CrossPlatformAccessibilityBrowserTest,
                        LocalizedLandmarkType) {
-  AccessibilityNotificationWaiter waiter(shell()->web_contents(),
-                                         ui::kAXModeComplete,
-                                         ax::mojom::Event::kLoadComplete);
-  GURL url(
-      "data:text/html,"
-      "<!doctype html>"
-      "<header aria-label='header'></header>"
-      "<aside aria-label='aside'></aside>"
-      "<footer aria-label='footer'></footer>"
-      "<form aria-label='form'></form>"
-      "<main aria-label='main'></main>"
-      "<nav aria-label='nav'></nav>"
-      "<section></section>"
-      "<section aria-label='section'></section>"
-      "<div role='banner' aria-label='banner'></div>"
-      "<div role='complementary' aria-label='complementary'></div>"
-      "<div role='contentinfo' aria-label='contentinfo'></div>"
-      "<div role='form' aria-label='role_form'></div>"
-      "<div role='main' aria-label='role_main'></div>"
-      "<div role='navigation' aria-label='role_nav'></div>"
-      "<div role='region'></div>"
-      "<div role='region' aria-label='region'></div>"
-      "<div role='search' aria-label='search'></div>");
-
-  EXPECT_TRUE(NavigateToURL(shell(), url));
-  waiter.WaitForNotification();
+  LoadInitialAccessibilityTreeFromHtml(R"HTML(
+      <!DOCTYPE html>
+      <html>
+      <body>
+        <header aria-label="header"></header>
+        <aside aria-label="aside"></aside>
+        <footer aria-label="footer"></footer>
+        <form aria-label="form"></form>
+        <main aria-label="main"></main>
+        <nav aria-label="nav"></nav>
+        <section></section>
+        <section aria-label="section"></section>
+        <div role="banner" aria-label="banner"></div>
+        <div role="complementary" aria-label="complementary"></div>
+        <div role="contentinfo" aria-label="contentinfo"></div>
+        <div role="form" aria-label="role_form"></div>
+        <div role="main" aria-label="role_main"></div>
+        <div role="navigation" aria-label="role_nav"></div>
+        <div role="region"></div>
+        <div role="region" aria-label="region"></div>
+        <div role="search" aria-label="search"></div>
+      </body>
+      </html>)HTML");
 
   BrowserAccessibility* root = GetManager()->GetRoot();
   ASSERT_NE(nullptr, root);
@@ -814,35 +835,33 @@ IN_PROC_BROWSER_TEST_F(CrossPlatformAccessibilityBrowserTest,
 #endif
 IN_PROC_BROWSER_TEST_F(CrossPlatformAccessibilityBrowserTest,
                        MAYBE_LocalizedRoleDescription) {
-  AccessibilityNotificationWaiter waiter(shell()->web_contents(),
-                                         ui::kAXModeComplete,
-                                         ax::mojom::Event::kLoadComplete);
-  GURL url(
-      "data:text/html,"
-      "<article></article>"
-      "<audio controls></audio>"
-      "<details></details>"
-      "<figure></figure>"
-      "<footer></footer>"
-      "<header></header>"
-      "<input>"
-      "<input type='color'>"
-      "<input type='date'>"
-      "<input type='datetime-local'>"
-      "<input type='email'>"
-      "<input type='tel'>"
-      "<input type='url'>"
-      "<input type='week'>"
-      "<mark></mark>"
-      "<meter></meter>"
-      "<output></output>"
-      "<section></section>"
-      "<section aria-label='section'></section>"
-      "<time></time>"
-      "<div role='contentinfo' aria-label='contentinfo'></div>");
-
-  EXPECT_TRUE(NavigateToURL(shell(), url));
-  waiter.WaitForNotification();
+  LoadInitialAccessibilityTreeFromHtml(R"HTML(
+      <!DOCTYPE html>
+      <html>
+      <body>
+        <article></article>
+        <audio controls></audio>
+        <details></details>
+        <figure></figure>
+        <footer></footer>
+        <header></header>
+        <input>
+        <input type="color">
+        <input type="date">
+        <input type="datetime-local">
+        <input type="email">
+        <input type="tel">
+        <input type="url">
+        <input type="week">
+        <mark></mark>
+        <meter></meter>
+        <output></output>
+        <section></section>
+        <section aria-label="section"></section>
+        <time></time>
+        <div role="contentinfo" aria-label="contentinfo"></div>
+      </body>
+      </html>)HTML");
 
   BrowserAccessibility* root = GetManager()->GetRoot();
   ASSERT_NE(nullptr, root);
@@ -885,16 +904,13 @@ IN_PROC_BROWSER_TEST_F(CrossPlatformAccessibilityBrowserTest,
 
 IN_PROC_BROWSER_TEST_F(CrossPlatformAccessibilityBrowserTest,
                        GetStyleNameAttributeAsLocalizedString) {
-  AccessibilityNotificationWaiter waiter(shell()->web_contents(),
-                                         ui::kAXModeComplete,
-                                         ax::mojom::Event::kLoadComplete);
-  GURL url(
-      "data:text/html,"
-      "<!doctype html>"
-      "<p>text <mark>mark text</mark></p>");
-
-  EXPECT_TRUE(NavigateToURL(shell(), url));
-  waiter.WaitForNotification();
+  LoadInitialAccessibilityTreeFromHtml(R"HTML(
+      <!DOCTYPE html>
+      <html>
+      <body>
+        <p>text <mark>mark text</mark></p>
+      </body>
+      </html>)HTML");
 
   BrowserAccessibility* root = GetManager()->GetRoot();
   ASSERT_NE(nullptr, root);
@@ -937,14 +953,15 @@ IN_PROC_BROWSER_TEST_F(CrossPlatformAccessibilityBrowserTest,
 
 IN_PROC_BROWSER_TEST_F(CrossPlatformAccessibilityBrowserTest,
                        TooltipStringAttributeMutuallyExclusiveOfNameFromTitle) {
-  const char url_str[] =
-      "data:text/html,"
-      "<!doctype html>"
-      "<input type='text' title='title'>"
-      "<input type='text' title='title' aria-labelledby='inputlabel'>"
-      "<div id='inputlabel'>aria-labelledby</div>";
-  GURL url(url_str);
-  EXPECT_TRUE(NavigateToURL(shell(), url));
+  LoadInitialAccessibilityTreeFromHtml(R"HTML(
+      <!DOCTYPE html>
+      <html>
+      <body>
+        <input type="text" title="title">
+        <input type="text" title="title" aria-labelledby="inputlabel">
+        <div id="inputlabel">aria-labelledby</div>
+      </body>
+      </html>)HTML");
 
   const ui::AXTree& tree = GetAXTree();
   const ui::AXNode* root = tree.root();
@@ -969,15 +986,16 @@ IN_PROC_BROWSER_TEST_F(CrossPlatformAccessibilityBrowserTest,
 IN_PROC_BROWSER_TEST_F(
     CrossPlatformAccessibilityBrowserTest,
     PlaceholderStringAttributeMutuallyExclusiveOfNameFromPlaceholder) {
-  const char url_str[] =
-      "data:text/html,"
-      "<!doctype html>"
-      "<fieldset>"
-      "<input type='text' placeholder='placeholder'>"
-      "<input type='text' placeholder='placeholder' aria-label='label'>"
-      "</fieldset>";
-  GURL url(url_str);
-  EXPECT_TRUE(NavigateToURL(shell(), url));
+  LoadInitialAccessibilityTreeFromHtml(R"HTML(
+      <!DOCTYPE html>
+      <html>
+      <body>
+        <fieldset>
+          <input type="text" placeholder="placeholder">
+          <input type="text" placeholder="placeholder" aria-label="label">
+        </fieldset>
+      </body>
+      </html>)HTML");
 
   const ui::AXTree& tree = GetAXTree();
   const ui::AXNode* root = tree.root();
@@ -1004,7 +1022,6 @@ IN_PROC_BROWSER_TEST_F(
 #if !defined(OS_ANDROID)
 IN_PROC_BROWSER_TEST_F(CrossPlatformAccessibilityBrowserTest,
                        GetBoundsRectUnclippedRootFrameFromIFrame) {
-  // Start by loading a document with iframes.
   LoadInitialAccessibilityTreeFromHtmlFilePath(
       "/accessibility/html/iframe-padding.html");
   WaitForAccessibilityTreeToContainNodeWithName(shell()->web_contents(),
@@ -1033,7 +1050,7 @@ IN_PROC_BROWSER_TEST_F(CrossPlatformAccessibilityBrowserTest,
                 .ToString());
 
   // Now get the root delegate of the iframe's accessibility tree.
-  AXTreeID iframe_tree_id = AXTreeID::FromString(
+  ui::AXTreeID iframe_tree_id = ui::AXTreeID::FromString(
       leaf_iframe_browser_accessibility->GetStringAttribute(
           ax::mojom::StringAttribute::kChildTreeId));
   BrowserAccessibilityManager* iframe_browser_accessibility_manager =
@@ -1056,7 +1073,6 @@ IN_PROC_BROWSER_TEST_F(CrossPlatformAccessibilityBrowserTest,
 
 IN_PROC_BROWSER_TEST_F(CrossPlatformAccessibilityBrowserTest,
                        GetBoundsRectUnclippedFrameFromIFrame) {
-  // Start by loading a document with iframes.
   LoadInitialAccessibilityTreeFromHtmlFilePath(
       "/accessibility/html/iframe-padding.html");
   WaitForAccessibilityTreeToContainNodeWithName(shell()->web_contents(),
@@ -1084,7 +1100,7 @@ IN_PROC_BROWSER_TEST_F(CrossPlatformAccessibilityBrowserTest,
                 .ToString());
 
   // Now get the root delegate of the iframe's accessibility tree.
-  AXTreeID iframe_tree_id = AXTreeID::FromString(
+  ui::AXTreeID iframe_tree_id = ui::AXTreeID::FromString(
       leaf_iframe_browser_accessibility->GetStringAttribute(
           ax::mojom::StringAttribute::kChildTreeId));
   BrowserAccessibilityManager* iframe_browser_accessibility_manager =
@@ -1105,26 +1121,17 @@ IN_PROC_BROWSER_TEST_F(CrossPlatformAccessibilityBrowserTest,
 }
 
 IN_PROC_BROWSER_TEST_F(CrossPlatformAccessibilityBrowserTest,
-                       TestControlsIdsForDateTimePopup) {
-  // Create a data url and load it.
-  const char url_str[] =
-      R"HTML(data:text/html,<!DOCTYPE html>
-        <html>
-          <div style="margin-top: 100px;"></div>
-          <input type="datetime-local" aria-label="datetime"
-                 aria-controls="button1">
-          <button id="button1">button</button>
-        </html>)HTML";
-  GURL url(url_str);
-
-  // Load the document and wait for it
-  {
-    AccessibilityNotificationWaiter waiter(shell()->web_contents(),
-                                           ui::kAXModeComplete,
-                                           ax::mojom::Event::kLoadComplete);
-    EXPECT_TRUE(NavigateToURL(shell(), url));
-    waiter.WaitForNotification();
-  }
+                       ControlsIdsForDateTimePopup) {
+  LoadInitialAccessibilityTreeFromHtml(R"HTML(
+      <!DOCTYPE html>
+      <html>
+      <body>
+        <div style="margin-top: 100px;"></div>
+        <input type="datetime-local" aria-label="datetime"
+               aria-controls="button1">
+        <button id="button1">button</button>
+      </body>
+      </html>)HTML");
 
   BrowserAccessibilityManager* manager = GetManager();
   ASSERT_NE(nullptr, manager);
@@ -1186,28 +1193,19 @@ IN_PROC_BROWSER_TEST_F(CrossPlatformAccessibilityBrowserTest,
 }
 
 IN_PROC_BROWSER_TEST_F(CrossPlatformAccessibilityBrowserTest,
-                       TestControlsIdsForColorPopup) {
-  // Create a data url and load it.
-  const char url_str[] =
-      R"HTML(data:text/html,<!DOCTYPE html>
-        <html>
-          <input type="color" aria-label="color" list="colorlist">
-          <datalist id="colorlist">
-            <option value="#ff0000">
-            <option value="#00ff00">
-            <option value="#0000ff">
-          </datalist>
-        </html>)HTML";
-  GURL url(url_str);
-
-  // Load the document and wait for it
-  {
-    AccessibilityNotificationWaiter waiter(shell()->web_contents(),
-                                           ui::kAXModeComplete,
-                                           ax::mojom::Event::kLoadComplete);
-    EXPECT_TRUE(NavigateToURL(shell(), url));
-    waiter.WaitForNotification();
-  }
+                       ControlsIdsForColorPopup) {
+  LoadInitialAccessibilityTreeFromHtml(R"HTML(
+      <!DOCTYPE html>
+      <html>
+      <body>
+        <input type="color" aria-label="color" list="colorlist">
+        <datalist id="colorlist">
+          <option value="#ff0000">
+          <option value="#00ff00">
+          <option value="#0000ff">
+        </datalist>
+      </body>
+      </html>)HTML");
 
   BrowserAccessibilityManager* manager = GetManager();
   ASSERT_NE(nullptr, manager);
@@ -1254,17 +1252,20 @@ IN_PROC_BROWSER_TEST_F(CrossPlatformAccessibilityBrowserTest,
 
 IN_PROC_BROWSER_TEST_F(CrossPlatformAccessibilityBrowserTest,
                        TextFragmentAnchor) {
-  EXPECT_TRUE(NavigateToURL(shell(), GURL(url::kAboutBlankURL)));
   AccessibilityNotificationWaiter anchor_waiter(
       shell()->web_contents(), ui::kAXModeComplete,
       ax::mojom::Event::kScrolledToAnchor);
 
-  GURL url(
-      "data:text/html,"
-      "<p>Some text</p>"
-      "<p id='target' style='position: absolute; top: 1000px'>Anchor text</p>"
-      "#:~:text=Anchor%20text");
-  EXPECT_TRUE(NavigateToURL(shell(), url));
+  GURL url(net::EscapeExternalHandlerValue(R"HTML(data:text/html,
+      <p>
+        Some text
+      </p>
+      <p id="target" style="position: absolute; top: 1000px">
+        Anchor text
+      </p>
+      #:~:text=Anchor text)HTML"));
+  ASSERT_TRUE(NavigateToURL(shell(), url));
+
   anchor_waiter.WaitForNotification();
   WaitForAccessibilityTreeToContainNodeWithName(shell()->web_contents(),
                                                 "Anchor text");
@@ -1279,16 +1280,23 @@ IN_PROC_BROWSER_TEST_F(CrossPlatformAccessibilityBrowserTest,
 }
 
 IN_PROC_BROWSER_TEST_F(CrossPlatformAccessibilityBrowserTest, GeneratedText) {
-  AccessibilityNotificationWaiter waiter(shell()->web_contents(),
-                                         ui::kAXModeComplete,
-                                         ax::mojom::Event::kLoadComplete);
-  GURL url(
-      "data:text/html,"
-      "<style>h1.generated::before{content:'   [   ';}"
-      "h1.generated::after{content:'   ]    ';}</style>"
-      "<h1 class='generated'>Foo</h1>");
-  EXPECT_TRUE(NavigateToURL(shell(), url));
-  waiter.WaitForNotification();
+  LoadInitialAccessibilityTreeFromHtml(R"HTML(
+      <!DOCTYPE html>
+      <html>
+      <head>
+        <style>
+          h1.generated::before {
+            content: "   [   ";
+          }
+          h1.generated::after {
+            content: "   ]    ";
+          }
+        </style>
+      </head>
+      <body>
+        <h1 class="generated">Foo</h1>
+      </body>
+      </html>)HTML");
 
   const BrowserAccessibility* root = GetManager()->GetRoot();
   ASSERT_EQ(1U, root->PlatformChildCount());
@@ -1370,7 +1378,6 @@ IN_PROC_BROWSER_TEST_F(CrossPlatformAccessibilityBrowserTest,
 
 IN_PROC_BROWSER_TEST_F(CrossPlatformAccessibilityBrowserTest,
                        IFrameContentHadFocus_ThenRootDocumentGainedFocus) {
-  // Start by loading a document with iframes.
   LoadInitialAccessibilityTreeFromHtmlFilePath(
       "/accessibility/html/iframe-padding.html");
   WaitForAccessibilityTreeToContainNodeWithName(shell()->web_contents(),
@@ -1425,6 +1432,12 @@ IN_PROC_BROWSER_TEST_F(CrossPlatformAccessibilityBrowserTest,
 
 class CrossPlatformAccessibilityBrowserTestWithImplicitRootScrolling
     : public CrossPlatformAccessibilityBrowserTest {
+ public:
+  CrossPlatformAccessibilityBrowserTestWithImplicitRootScrolling() = default;
+  ~CrossPlatformAccessibilityBrowserTestWithImplicitRootScrolling() override =
+      default;
+
+ protected:
   void ChooseFeatures(std::vector<base::Feature>* enabled_features,
                       std::vector<base::Feature>* disabled_features) override {
     enabled_features->emplace_back(blink::features::kImplicitRootScroller);
@@ -1475,35 +1488,30 @@ IN_PROC_BROWSER_TEST_F(CrossPlatformAccessibilityBrowserTest,
                        NonInteractiveChangesAreBatched) {
   // Ensure that normal DOM changes are batched together, and do not occur
   // more than once every kDelayForDeferredUpdatesAfterPageLoad.
-  const char url_str[] =
-      R"HTML(data:text/html,
-      <!doctype html>
-      <body><div id=foo></div>
-      <script>
-      const startTime = performance.now();
-      const fooElem = document.getElementById('foo');
-      function addChild() {
-        const newChild = document.createElement('div');
-        newChild.innerHTML = '<button>x</button>';
-        fooElem.appendChild(newChild);
-        if (performance.now() - startTime < 1000)
-          requestAnimationFrame(addChild);
-        else
-          document.close();
-      }
-      addChild();
-      </script>
-      </body></html>)HTML";
-  GURL url(url_str);
-
-  // Load the document and wait for it
-  {
-    AccessibilityNotificationWaiter waiter(shell()->web_contents(),
-                                           ui::kAXModeComplete,
-                                           ax::mojom::Event::kLoadComplete);
-    EXPECT_TRUE(NavigateToURL(shell(), url));
-    waiter.WaitForNotification();
-  }
+  LoadInitialAccessibilityTreeFromHtml(R"HTML(
+      <!DOCTYPE html>
+      <html>
+      <body>
+        <div id="foo">
+        </div>
+        <script>
+          const startTime = performance.now();
+          const fooElem = document.getElementById('foo');
+          function addChild() {
+            const newChild = document.createElement('div');
+            newChild.innerHTML = '<button>x</button>';
+            fooElem.appendChild(newChild);
+            if (performance.now() - startTime < 1000) {
+              requestAnimationFrame(addChild);
+            } else {
+              document.close();
+            }
+          }
+          addChild();
+        </script>
+      </body>
+      </html>)HTML");
+
   base::ElapsedTimer timer;
   int num_batches = 0;
 
@@ -1531,50 +1539,42 @@ IN_PROC_BROWSER_TEST_F(CrossPlatformAccessibilityBrowserTest,
                        DocumentSelectionChangesAreNotBatched) {
   // Ensure that document selection changes are not batched, and occur faster
   // than once per kDelayForDeferredUpdatesAfterPageLoad.
-  const char url_str[] =
-      R"HTML(data:text/html,
-      <!doctype html>
-      <body><div id=foo></div>
-      <script>
-      const startTime = performance.now();
-      const fooElem = document.getElementById('foo');
-      function addChild() {
-        const newChild = document.createElement('div');
-        newChild.innerHTML = '<button>x</button>';
-        fooElem.appendChild(newChild);
-        window.getSelection().selectAllChildren(newChild);
-        if (performance.now() - startTime < 1000)
-          requestAnimationFrame(addChild);
-        else
-          document.close();
-      }
-      addChild();
-      </script>
-      </body></html>)HTML";
-  GURL url(url_str);
-
-  // Load the document and wait for it
-  {
-    AccessibilityNotificationWaiter waiter(shell()->web_contents(),
-                                           ui::kAXModeComplete,
-                                           ax::mojom::Event::kLoadComplete);
-    EXPECT_TRUE(NavigateToURL(shell(), url));
-    waiter.WaitForNotification();
-  }
+  LoadInitialAccessibilityTreeFromHtml(R"HTML(
+      <!DOCTYPE html>
+      <html>
+      <body>
+        <div id="foo">
+        </div>
+        <script>
+          const startTime = performance.now();
+          const fooElem = document.getElementById('foo');
+          function addChild() {
+            const newChild = document.createElement('div');
+            newChild.innerHTML = '<button>x</button>';
+            fooElem.appendChild(newChild);
+            window.getSelection().selectAllChildren(newChild);
+            if (performance.now() - startTime < 1000) {
+              requestAnimationFrame(addChild);
+            } else {
+              document.close();
+            }
+          }
+          addChild();
+        </script>
+      </body>
+      </html>)HTML");
 
   base::ElapsedTimer timer;
   int num_batches = 0;
 
-  {
-    AccessibilityNotificationWaiter waiter(shell()->web_contents(),
-                                           ui::kAXModeComplete,
-                                           ax::mojom::Event::kLayoutComplete);
-    // Run test for 1 second, counting the number of layout completes.
-    while (timer.Elapsed().InMilliseconds() < 1000) {
-      waiter.WaitForNotificationWithTimeout(
-          base::TimeDelta::FromMilliseconds(1000) - timer.Elapsed());
-      ++num_batches;
-    }
+  AccessibilityNotificationWaiter waiter(
+      shell()->web_contents(), ui::kAXModeComplete,
+      ax::mojom::Event::kDocumentSelectionChanged);
+  // Run test for 1 second, counting the number of selection changes.
+  while (timer.Elapsed().InMilliseconds() < 1000) {
+    waiter.WaitForNotificationWithTimeout(
+        base::TimeDelta::FromMilliseconds(1000) - timer.Elapsed());
+    ++num_batches;
   }
 
   // In practice, num_batches is about 50 on a fast Linux box.
@@ -1587,38 +1587,32 @@ IN_PROC_BROWSER_TEST_F(CrossPlatformAccessibilityBrowserTest,
                        ActiveDescendantChangesAreNotBatched) {
   // Ensure that active descendant changes are not batched, and occur faster
   // than once per kDelayForDeferredUpdatesAfterPageLoad.
-  const char url_str[] =
-      R"HTML(data:text/html,
-      <!doctype html>
-      <body><div id=foo tabindex=0 autofocus></div>
-      <script>
-      const startTime = performance.now();
-      const fooElem = document.getElementById('foo');
-      let count = 0;
-      function addChild() {
-        const newChild = document.createElement('div');
-        ++count;
-        newChild.innerHTML = '<button id=' + count + '>x</button>';
-        fooElem.appendChild(newChild);
-        fooElem.setAttribute('aria-activedescendant', count);
-        if (performance.now() - startTime < 1000)
-          requestAnimationFrame(addChild);
-        else
-          document.close();
-      }
-      addChild();
-      </script>
-      </body></html>)HTML";
-  GURL url(url_str);
-
-  // Load the document and wait for it
-  {
-    AccessibilityNotificationWaiter waiter(shell()->web_contents(),
-                                           ui::kAXModeComplete,
-                                           ax::mojom::Event::kLoadComplete);
-    EXPECT_TRUE(NavigateToURL(shell(), url));
-    waiter.WaitForNotification();
-  }
+  LoadInitialAccessibilityTreeFromHtml(R"HTML(
+      <!DOCTYPE html>
+      <html>
+      <body>
+        <div id="foo" tabindex="0" autofocus>
+        </div>
+        <script>
+          const startTime = performance.now();
+          const fooElem = document.getElementById('foo');
+          let count = 0;
+          function addChild() {
+            const newChild = document.createElement('div');
+            ++count;
+            newChild.innerHTML = '<button id=' + count + '>x</button>';
+            fooElem.appendChild(newChild);
+            fooElem.setAttribute('aria-activedescendant', count);
+            if (performance.now() - startTime < 1000) {
+              requestAnimationFrame(addChild);
+            } else {
+              document.close();
+            }
+          }
+          addChild();
+        </script>
+      </body>
+      </html>)HTML");
 
   base::ElapsedTimer timer;
   int num_batches = 0;
@@ -1647,13 +1641,15 @@ IN_PROC_BROWSER_TEST_F(CrossPlatformAccessibilityBrowserTest,
   // listener to it we can make it no longer ignored without correctly firing
   // the right notifications - with the end result being that the whole
   // accessibility tree is broken.
-  LoadInitialAccessibilityTreeFromUrl(GURL(R"HTML(data:text/html,
+  LoadInitialAccessibilityTreeFromHtml(R"HTML(
       <!DOCTYPE html>
+      <html>
       <body>
         <div>
           <button>This should be accessible</button>
         </div>
-      </body></html>)HTML"));
+      </body>
+      </html>)HTML");
 
   BrowserAccessibilityManager* browser_accessibility_manager = GetManager();
   BrowserAccessibility* root_browser_accessibility =