Make SVG elements in Chrome clickable by assistive technology.

This change implements the AccessKeyAction method for SVG elements
to make them clickable by assistive technologies.

Bug: 958553
Change-Id: I604379586fe866e666216fe58b703c157457b27f
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/1691325
Commit-Queue: Akihiro Ota <akihiroota@chromium.org>
Reviewed-by: Nektarios Paisios <nektar@chromium.org>
Reviewed-by: Jochen Eisinger <jochen@chromium.org>
Cr-Commit-Position: refs/heads/master@{#678029}

content/browser/accessibility/accessibility_action_browsertest.cc

@@ -801,4 +801,34 @@ IN_PROC_BROWSER_TEST_F(AccessibilityActionBrowserTest, ScrollIntoView) {
 }
 #endif  // !defined(OS_ANDROID)
 
+IN_PROC_BROWSER_TEST_F(AccessibilityActionBrowserTest, ClickSVG) {
+  // Create an svg link element that has the shape of a small, red square.
+  LoadInitialAccessibilityTreeFromHtml(R"HTML(
+      <svg aria-label="svg" width="10" height="10" viewBox="0 0 10 10"
+        onclick="(function() {
+          let para = document.createElement('p');
+          para.innerHTML = 'SVG link was clicked!';
+          document.body.appendChild(para);})()">
+        <a xlink:href="#">
+          <path fill-opacity="1" fill="#ff0000"
+            d="M 0 0 L 10 0 L 10 10 L 0 10 Z"></path>
+        </a>
+      </svg>
+      )HTML");
+
+  AccessibilityNotificationWaiter click_waiter(
+      shell()->web_contents(), ui::kAXModeComplete, ax::mojom::Event::kClicked);
+  BrowserAccessibility* target_node =
+      FindNode(ax::mojom::Role::kSvgRoot, "svg");
+  ASSERT_NE(target_node, nullptr);
+  GetManager()->DoDefaultAction(*target_node);
+  click_waiter.WaitForNotification();
+#if !defined(OS_ANDROID)
+  // This waiter times out on some Android try bots.
+  // TODO(akihiroota): Refactor test to be applicable to all platforms.
+  WaitForAccessibilityTreeToContainNodeWithName(shell()->web_contents(),
+                                                "SVG link was clicked!");
+#endif  // !defined(OS_ANDROID)
+}
+
 }  // namespace content

third_party/blink/renderer/core/svg/svg_element.cc

@@ -1328,4 +1328,9 @@ void SVGElement::Trace(blink::Visitor* visitor) {
   Element::Trace(visitor);
 }
 
+void SVGElement::AccessKeyAction(bool send_mouse_events) {
+  DispatchSimulatedClick(
+      nullptr, send_mouse_events ? kSendMouseUpDownEvents : kSendNoEvents);
+}
+
 }  // namespace blink

third_party/blink/renderer/core/svg/svg_element.h

@@ -264,6 +264,8 @@ class CORE_EXPORT SVGElement : public Element {
   void RemovedEventListener(const AtomicString& event_type,
                             const RegisteredEventListener&) final;
 
+  void AccessKeyAction(bool send_mouse_events) override;
+
  private:
   bool IsSVGElement() const =
       delete;  // This will catch anyone doing an unnecessary check.