Implement caching asynchronous accessibility hit testing.

content/browser/accessibility/hit_testing_browsertest.cc

Index: content/browser/accessibility/hit_testing_browsertest.cc
diff --git a/content/browser/accessibility/hit_testing_browsertest.cc b/content/browser/accessibility/hit_testing_browsertest.cc
index f1e6d9e3179e9836e83bf9cb9bec2a4d70a810e6..0951785ceb974bddd5867eaad8eb6de87335c3ff 100644
--- a/content/browser/accessibility/hit_testing_browsertest.cc
+++ b/content/browser/accessibility/hit_testing_browsertest.cc
@@ -2,28 +2,14 @@
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
-#include <set>
-#include <string>
-#include <vector>
-
-#include "base/command_line.h"
-#include "base/files/file_util.h"
 #include "base/logging.h"
-#include "base/strings/string16.h"
-#include "base/strings/string_split.h"
-#include "base/strings/string_util.h"
-#include "base/strings/utf_string_conversions.h"
-#include "content/browser/accessibility/accessibility_tree_formatter.h"
 #include "content/browser/accessibility/browser_accessibility.h"
 #include "content/browser/accessibility/browser_accessibility_manager.h"
 #include "content/browser/web_contents/web_contents_impl.h"
-#include "content/public/browser/web_contents.h"
-#include "content/public/common/content_paths.h"
-#include "content/public/common/content_switches.h"
-#include "content/public/common/url_constants.h"
 #include "content/public/test/browser_test_utils.h"
 #include "content/public/test/content_browser_test.h"
 #include "content/public/test/content_browser_test_utils.h"
+#include "content/public/test/test_utils.h"
 #include "content/shell/browser/shell.h"
 #include "content/test/accessibility_browser_test_utils.h"
 #include "net/dns/mock_host_resolver.h"
@@ -59,6 +45,26 @@ class AccessibilityHitTestingBrowserTest : public ContentBrowserTest {
         target_manager->GetFromID(hover_target_id);
     return hovered_node;
   }
+
+  BrowserAccessibility* CallCachingAsyncHitTest(const gfx::Point& point) {
+    WebContentsImpl* web_contents =
+        static_cast<WebContentsImpl*>(shell()->web_contents());
+    FrameTree* frame_tree = web_contents->GetFrameTree();
+    BrowserAccessibilityManager* manager =
+        web_contents->GetRootBrowserAccessibilityManager();
+    gfx::Point screen_point =
+        point + manager->GetViewBounds().OffsetFromOrigin();
+
+    // Each call to CachingAsyncHitTest results in at least one HOVER
+    // event received. Block until we receive it.
+    AccessibilityNotificationWaiter hover_waiter(
+        shell()->web_contents(), AccessibilityModeComplete, ui::AX_EVENT_HOVER);
+    for (FrameTreeNode* node : frame_tree->Nodes())
+      hover_waiter.ListenToAdditionalFrame(node->current_frame_host());
+    BrowserAccessibility* result = manager->CachingAsyncHitTest(screen_point);
+    hover_waiter.WaitForNotification();
+    return result;
+  }
 };
 
 IN_PROC_BROWSER_TEST_F(AccessibilityHitTestingBrowserTest,
@@ -144,4 +150,72 @@ IN_PROC_BROWSER_TEST_F(AccessibilityHitTestingBrowserTest,
   ASSERT_EQ(ui::AX_ROLE_DIV, hovered_node->GetRole());
 }
 
+IN_PROC_BROWSER_TEST_F(AccessibilityHitTestingBrowserTest,
+                       CachingAsyncHitTestingInIframes) {
+  host_resolver()->AddRule("*", "127.0.0.1");
+  ASSERT_TRUE(embedded_test_server()->Start());
+
+  NavigateToURL(shell(), GURL(url::kAboutBlankURL));
+
+  AccessibilityNotificationWaiter waiter(shell()->web_contents(),
+                                         AccessibilityModeComplete,
+                                         ui::AX_EVENT_LOAD_COMPLETE);
+  GURL url(embedded_test_server()->GetURL(
+      "/accessibility/hit_testing/hit_testing.html"));
+  NavigateToURL(shell(), url);
+  waiter.WaitForNotification();
+
+  WaitForAccessibilityTreeToContainNodeWithName(
+      shell()->web_contents(), "Ordinary Button");
+  WaitForAccessibilityTreeToContainNodeWithName(
+      shell()->web_contents(), "Scrolled Button");
+
+  // For each point we try, the first time we call CachingAsyncHitTest it
+  // should FAIL and return the wrong object, because this test page has
+  // been designed to confound local synchronous hit testing using
+  // z-indexes. However, calling CachingAsyncHitTest a second time should
+  // return the correct result (since CallCachingAsyncHitTest waits for the
+  // HOVER event to be received).
+
+  // (50, 50) -> "Button"
+  BrowserAccessibility* hovered_node;
+  hovered_node = CallCachingAsyncHitTest(gfx::Point(50, 50));
+  ASSERT_TRUE(hovered_node != NULL);
+  ASSERT_NE(ui::AX_ROLE_BUTTON, hovered_node->GetRole());
+  hovered_node = CallCachingAsyncHitTest(gfx::Point(50, 50));
+  ASSERT_EQ("Button", hovered_node->GetStringAttribute(ui::AX_ATTR_NAME));
+
+  // (50, 305) -> div in first iframe
+  hovered_node = CallCachingAsyncHitTest(gfx::Point(50, 305));
+  ASSERT_TRUE(hovered_node != NULL);
+  ASSERT_NE(ui::AX_ROLE_DIV, hovered_node->GetRole());
+  hovered_node = CallCachingAsyncHitTest(gfx::Point(50, 305));
+  ASSERT_EQ(ui::AX_ROLE_DIV, hovered_node->GetRole());
+
+  // (50, 350) -> "Ordinary Button"
+  hovered_node = CallCachingAsyncHitTest(gfx::Point(50, 350));
+  ASSERT_TRUE(hovered_node != NULL);
+  ASSERT_NE(ui::AX_ROLE_BUTTON, hovered_node->GetRole());
+  hovered_node = CallCachingAsyncHitTest(gfx::Point(50, 350));
+  ASSERT_EQ(ui::AX_ROLE_BUTTON, hovered_node->GetRole());
+  ASSERT_EQ("Ordinary Button",
+            hovered_node->GetStringAttribute(ui::AX_ATTR_NAME));
+
+  // (50, 455) -> "Scrolled Button"
+  hovered_node = CallCachingAsyncHitTest(gfx::Point(50, 455));
+  ASSERT_TRUE(hovered_node != NULL);
+  ASSERT_NE(ui::AX_ROLE_BUTTON, hovered_node->GetRole());
+  hovered_node = CallCachingAsyncHitTest(gfx::Point(50, 455));
+  ASSERT_EQ(ui::AX_ROLE_BUTTON, hovered_node->GetRole());
+  ASSERT_EQ("Scrolled Button",
+            hovered_node->GetStringAttribute(ui::AX_ATTR_NAME));
+
+  // (50, 505) -> div in second iframe
+  hovered_node = CallCachingAsyncHitTest(gfx::Point(50, 505));
+  ASSERT_TRUE(hovered_node != NULL);
+  ASSERT_NE(ui::AX_ROLE_DIV, hovered_node->GetRole());
+  hovered_node = CallCachingAsyncHitTest(gfx::Point(50, 505));
+  ASSERT_EQ(ui::AX_ROLE_DIV, hovered_node->GetRole());
+}
+
 }  // namespace content