chromeos: Move AXHostService into ash

This is a step toward supporting multiple remote apps and widgets. We
need this for browser windows under single-process-mash.

Under mash the ash process is responsible for top-level window creation
for remote apps. It will need to route accessibility actions (like hit
testing) to the correct remote app. Likewise it manages window frames
and focus. Therefore it should own the mojo AXHostService, not the
browser.

Accessibility events from the remote app must be routed out of ash
into chrome to the accessibility extension. For now we do this with
the in-process AccessibilityDelegate. I didn't introduce a new delegate
because the mojo service is lazily created and it's hard to connect
a new delegate at startup. Subsequent CLs will:
* Always create the service at ash startup
* Convert the delegate methods to mojo

See go/mash-ax-node-tree for the full plan.

Bug: 888147
Test: ash_unittests, manually use ChromeVox and STS with shortcut viewer
Change-Id: Ia9e63689a8cb407b66397778be4617479fdf6c92
Reviewed-on: https://chromium-review.googlesource.com/1249920
Commit-Queue: James Cook <jamescook@chromium.org>
Reviewed-by: Scott Violet <sky@chromium.org>
Reviewed-by: David Tseng <dtseng@chromium.org>
Cr-Commit-Position: refs/heads/master@{#594949}

ash/BUILD.gn

@@ -34,6 +34,7 @@ component("ash") {
     "accelerators/accelerator_controller.h",
     "accessibility/accessibility_controller.h",
     "accessibility/accessibility_delegate.h",
+    "accessibility/ax_host_service.h",
     "accessibility/focus_ring_controller.h",
     "app_list/app_list_controller_impl.h",
     "detachable_base/detachable_base_handler.h",
@@ -131,6 +132,7 @@ component("ash") {
     "accessibility/accessibility_observer.h",
     "accessibility/accessibility_panel_layout_manager.cc",
     "accessibility/accessibility_panel_layout_manager.h",
+    "accessibility/ax_host_service.cc",
     "accessibility/default_accessibility_delegate.cc",
     "accessibility/default_accessibility_delegate.h",
     "accessibility/focus_ring_controller.cc",
@@ -1687,6 +1689,7 @@ test("ash_unittests") {
     "accessibility/accessibility_focus_ring_group_unittest.cc",
     "accessibility/accessibility_highlight_controller_unittest.cc",
     "accessibility/accessibility_panel_layout_manager_unittest.cc",
+    "accessibility/ax_host_service_unittest.cc",
     "accessibility/key_accessibility_enabler_unittest.cc",
     "accessibility/touch_accessibility_enabler_unittest.cc",
     "accessibility/touch_exploration_controller_unittest.cc",

ash/accessibility/accessibility_delegate.h

@@ -5,9 +5,15 @@
 #ifndef ASH_ACCESSIBILITY_ACCESSIBILITY_DELEGATE_H_
 #define ASH_ACCESSIBILITY_ACCESSIBILITY_DELEGATE_H_
 
+#include <vector>
+
 #include "ash/ash_export.h"
-#include "base/time/time.h"
-#include "ui/accessibility/ax_enums.mojom.h"
+#include "ui/accessibility/ax_tree_id.h"
+#include "ui/accessibility/ax_tree_update.h"
+
+namespace ui {
+struct AXEvent;
+}
 
 namespace ash {
 
@@ -36,6 +42,14 @@ class ASH_EXPORT AccessibilityDelegate {
   // is not saved, return a negative value.
   virtual double GetSavedScreenMagnifierScale() = 0;
 
+  // Automation API support for remote mojo apps.
+  // TODO(jamescook): Convert to mojo API.
+  virtual void DispatchAccessibilityEvent(
+      const ui::AXTreeID& tree_id,
+      const std::vector<ui::AXTreeUpdate>& updates,
+      const ui::AXEvent& event) = 0;
+  virtual void DispatchTreeDestroyedEvent(const ui::AXTreeID& tree_id) = 0;
+
   // NOTE: Prefer adding methods to AccessibilityController, see class comment.
 };
 

chrome/browser/chromeos/accessibility/ax_host_service.cc → ash/accessibility/ax_host_service.cc

@@ -2,19 +2,19 @@
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
-#include "chrome/browser/chromeos/accessibility/ax_host_service.h"
+#include "ash/accessibility/ax_host_service.h"
 
 #include "ash/accessibility/accessibility_controller.h"
+#include "ash/accessibility/accessibility_delegate.h"
 #include "ash/shell.h"
 #include "base/bind.h"
-#include "chrome/browser/extensions/api/automation_internal/automation_event_router.h"
-#include "chrome/common/extensions/chrome_extension_messages.h"
 #include "services/service_manager/public/cpp/connector.h"
 #include "services/service_manager/public/cpp/service_context.h"
 #include "ui/accessibility/ax_event.h"
-#include "ui/aura/env.h"
 #include "ui/views/mus/ax_remote_host.h"
 
+namespace ash {
+
 AXHostService* AXHostService::instance_ = nullptr;
 
 bool AXHostService::automation_enabled_ = false;
@@ -23,12 +23,8 @@ AXHostService::AXHostService() {
   // AX tree ID is automatically assigned.
   DCHECK(!tree_id().empty());
 
-  // ash::Shell may not exist in tests.
-  if (ash::Shell::HasInstance()) {
-    // TODO(jamescook): Eliminate this when tree ID assignment is handed in ash.
-    ash::Shell::Get()->accessibility_controller()->set_remote_ax_tree_id(
-        tree_id());
-  }
+  // TODO(jamescook): Eliminate this when multiple remote trees are supported.
+  Shell::Get()->accessibility_controller()->set_remote_ax_tree_id(tree_id());
 
   DCHECK(!instance_);
   instance_ = this;
@@ -71,16 +67,12 @@ void AXHostService::HandleAccessibilityEvent(
     const std::vector<ui::AXTreeUpdate>& updates,
     const ui::AXEvent& event) {
   CHECK_EQ(tree_id, this->tree_id());
-  ExtensionMsg_AccessibilityEventBundleParams event_bundle;
-  event_bundle.tree_id = tree_id;
-  for (const ui::AXTreeUpdate& update : updates)
-    event_bundle.updates.push_back(update);
-  event_bundle.events.push_back(event);
-  event_bundle.mouse_location = aura::Env::GetInstance()->last_mouse_location();
-
-  // Forward the tree updates and the event to the accessibility extension.
-  extensions::AutomationEventRouter::GetInstance()->DispatchAccessibilityEvents(
-      event_bundle);
+  // Use an in-process delegate back to Chrome for efficiency in classic ash.
+  // For mash we'll need to pass around a mojo interface pointer such that a
+  // remote app can talk directly to the browser process and not ping-pong
+  // through the ash process.
+  Shell::Get()->accessibility_delegate()->DispatchAccessibilityEvent(
+      tree_id, updates, event);
 }
 
 void AXHostService::PerformAction(const ui::AXActionData& data) {
@@ -104,6 +96,7 @@ void AXHostService::NotifyAutomationEnabled() {
 }
 
 void AXHostService::OnRemoteHostDisconnected() {
-  extensions::AutomationEventRouter::GetInstance()->DispatchTreeDestroyedEvent(
-      tree_id(), nullptr /* browser_context */);
+  Shell::Get()->accessibility_delegate()->DispatchTreeDestroyedEvent(tree_id());
 }
+
+}  // namespace ash

chrome/browser/chromeos/accessibility/ax_host_service.h → ash/accessibility/ax_host_service.h

@@ -2,26 +2,30 @@
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
-#ifndef CHROME_BROWSER_CHROMEOS_ACCESSIBILITY_AX_HOST_SERVICE_H_
-#define CHROME_BROWSER_CHROMEOS_ACCESSIBILITY_AX_HOST_SERVICE_H_
+#ifndef ASH_ACCESSIBILITY_AX_HOST_SERVICE_H_
+#define ASH_ACCESSIBILITY_AX_HOST_SERVICE_H_
 
 #include <memory>
 
+#include "ash/ash_export.h"
 #include "mojo/public/cpp/bindings/binding_set.h"
 #include "mojo/public/cpp/bindings/interface_ptr_set.h"
 #include "services/service_manager/public/cpp/binder_registry.h"
 #include "services/service_manager/public/cpp/service.h"
 #include "ui/accessibility/ax_host_delegate.h"
+#include "ui/accessibility/ax_tree_id.h"
 #include "ui/accessibility/mojom/ax_host.mojom.h"
 
+namespace ash {
+
 // Forwards accessibility events from clients in other processes that use aura
 // and views (e.g. the Chrome OS keyboard shortcut_viewer) to accessibility
 // extensions. Renderers, PDF, etc. use a different path. Created when the first
 // client connects over mojo. Implements AXHostDelegate by routing actions over
 // mojo to the remote process.
-class AXHostService : public service_manager::Service,
-                      public ax::mojom::AXHost,
-                      public ui::AXHostDelegate {
+class ASH_EXPORT AXHostService : public service_manager::Service,
+                                 public ax::mojom::AXHost,
+                                 public ui::AXHostDelegate {
  public:
   AXHostService();
   ~AXHostService() override;
@@ -66,4 +70,6 @@ class AXHostService : public service_manager::Service,
   DISALLOW_COPY_AND_ASSIGN(AXHostService);
 };
 
-#endif  // CHROME_BROWSER_CHROMEOS_ACCESSIBILITY_AX_HOST_SERVICE_H_
+}  // namespace ash
+
+#endif  // ASH_ACCESSIBILITY_AX_HOST_SERVICE_H_

chrome/browser/chromeos/accessibility/ax_host_service_unittest.cc → ash/accessibility/ax_host_service_unittest.cc

@@ -2,15 +2,17 @@
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
-#include "chrome/browser/chromeos/accessibility/ax_host_service.h"
+#include "ash/accessibility/ax_host_service.h"
 
+#include "ash/test/ash_test_base.h"
 #include "base/bind.h"
 #include "base/macros.h"
 #include "base/test/scoped_task_environment.h"
 #include "mojo/public/cpp/bindings/binding.h"
 #include "testing/gtest/include/gtest/gtest.h"
 #include "ui/accessibility/mojom/ax_host.mojom.h"
 
+namespace ash {
 namespace {
 
 class TestAXRemoteHost : ax::mojom::AXRemoteHost {
@@ -51,16 +53,7 @@ class TestAXRemoteHost : ax::mojom::AXRemoteHost {
   DISALLOW_COPY_AND_ASSIGN(TestAXRemoteHost);
 };
 
-class AXHostServiceTest : public testing::Test {
- public:
-  AXHostServiceTest() = default;
-  ~AXHostServiceTest() override = default;
-
- private:
-  base::test::ScopedTaskEnvironment scoped_task_enviroment_;
-
-  DISALLOW_COPY_AND_ASSIGN(AXHostServiceTest);
-};
+using AXHostServiceTest = AshTestBase;
 
 TEST_F(AXHostServiceTest, AddClientThenEnable) {
   AXHostService service;
@@ -120,3 +113,4 @@ TEST_F(AXHostServiceTest, PerformAction) {
 }
 
 }  // namespace
+}  // namespace ash

ash/accessibility/default_accessibility_delegate.cc

@@ -40,4 +40,12 @@ double DefaultAccessibilityDelegate::GetSavedScreenMagnifierScale() {
   return std::numeric_limits<double>::min();
 }
 
+void DefaultAccessibilityDelegate::DispatchAccessibilityEvent(
+    const ui::AXTreeID& tree_id,
+    const std::vector<ui::AXTreeUpdate>& updates,
+    const ui::AXEvent& event) {}
+
+void DefaultAccessibilityDelegate::DispatchTreeDestroyedEvent(
+    const ui::AXTreeID& tree_id) {}
+
 }  // namespace ash

ash/accessibility/default_accessibility_delegate.h

@@ -11,6 +11,7 @@
 
 namespace ash {
 
+// Used in tests and non-production code like ash_shell_with_content.
 class ASH_EXPORT DefaultAccessibilityDelegate : public AccessibilityDelegate {
  public:
   DefaultAccessibilityDelegate();
@@ -21,6 +22,10 @@ class ASH_EXPORT DefaultAccessibilityDelegate : public AccessibilityDelegate {
   bool ShouldShowAccessibilityMenu() const override;
   void SaveScreenMagnifierScale(double scale) override;
   double GetSavedScreenMagnifierScale() override;
+  void DispatchAccessibilityEvent(const ui::AXTreeID& tree_id,
+                                  const std::vector<ui::AXTreeUpdate>& updates,
+                                  const ui::AXEvent& event) override;
+  void DispatchTreeDestroyedEvent(const ui::AXTreeID& tree_id) override;
 
  private:
   bool screen_magnifier_enabled_ = false;

ash/ash_service.cc

@@ -203,6 +203,7 @@ void AshService::CreateService(
     service_manager::mojom::ServiceRequest service,
     const std::string& name,
     service_manager::mojom::PIDReceiverPtr pid_receiver) {
+  // TODO(jamescook): Create the AXHostService here under mash.
   DCHECK_EQ(name, ws::mojom::kServiceName);
   Shell::Get()->window_service_owner()->BindWindowService(std::move(service));
   if (base::FeatureList::IsEnabled(features::kMash)) {

chrome/browser/DEPS

@@ -215,11 +215,8 @@ include_rules = [
 
 specific_include_rules = {
   "ash_service_registry\.cc": [
-    # The following are needed for classic mode to create the WindowService.
-    # Once Ash runs out of process no longer needed.
-    "+ash/shell.h",
-
     # Needed for classic mode.
+    "+ash/accessibility/ax_host_service.h",
     "+ash/ash_service.h",
   ],
   # TODO(mash): Fix. https://crbug.com/768439, https://crbug.com/768395.

chrome/browser/ash_service_registry.cc

@@ -4,6 +4,7 @@
 
 #include "chrome/browser/ash_service_registry.h"
 
+#include "ash/accessibility/ax_host_service.h"
 #include "ash/ash_service.h"
 #include "ash/components/quick_launch/public/mojom/constants.mojom.h"
 #include "ash/components/shortcut_viewer/public/mojom/shortcut_viewer.mojom.h"
@@ -15,7 +16,6 @@
 #include "base/strings/utf_string_conversions.h"
 #include "base/threading/thread_task_runner_handle.h"
 #include "build/build_config.h"
-#include "chrome/browser/chromeos/accessibility/ax_host_service.h"
 #include "chrome/browser/chromeos/prefs/pref_connector_service.h"
 #include "chrome/grit/generated_resources.h"
 #include "content/public/common/service_manager_connection.h"
@@ -84,20 +84,20 @@ void RegisterInProcessServices(
     (*services)[ash::mojom::kPrefConnectorServiceName] = info;
   }
 
+  if (features::IsMultiProcessMash())
+    return;
+
   {
     // Register the accessibility host service.
     service_manager::EmbeddedServiceInfo info;
     info.task_runner = base::ThreadTaskRunnerHandle::Get();
     info.factory =
         base::BindRepeating([]() -> std::unique_ptr<service_manager::Service> {
-          return std::make_unique<AXHostService>();
+          return std::make_unique<ash::AXHostService>();
         });
     (*services)[ax::mojom::kAXHostServiceName] = info;
   }
 
-  if (features::IsMultiProcessMash())
-    return;
-
   (*services)[ash::mojom::kServiceName] =
       ash::AshService::CreateEmbeddedServiceInfo();
 }

chrome/browser/chromeos/BUILD.gn

@@ -263,8 +263,6 @@ source_set("chromeos") {
     "accessibility/accessibility_manager.h",
     "accessibility/accessibility_panel.cc",
     "accessibility/accessibility_panel.h",
-    "accessibility/ax_host_service.cc",
-    "accessibility/ax_host_service.h",
     "accessibility/chromevox_panel.cc",
     "accessibility/chromevox_panel.h",
     "accessibility/dictation_chromeos.cc",
@@ -2019,7 +2017,6 @@ source_set("unit_tests") {
     "../policy/default_geolocation_policy_handler_unittest.cc",
     "../resources/chromeos/zip_archiver/test/char_coding_test.cc",
     "../ui/browser_finder_chromeos_unittest.cc",
-    "accessibility/ax_host_service_unittest.cc",
     "app_mode/startup_app_launcher_unittest.cc",
     "apps/intent_helper/apps_navigation_throttle_unittest.cc",
     "apps/intent_helper/page_transition_util_unittest.cc",

chrome/browser/ui/ash/chrome_accessibility_delegate.cc

@@ -8,6 +8,9 @@
 
 #include "chrome/browser/chromeos/accessibility/accessibility_manager.h"
 #include "chrome/browser/chromeos/accessibility/magnification_manager.h"
+#include "chrome/browser/extensions/api/automation_internal/automation_event_router.h"
+#include "chrome/common/extensions/chrome_extension_messages.h"
+#include "ui/aura/env.h"
 
 using chromeos::AccessibilityManager;
 using chromeos::MagnificationManager;
@@ -42,3 +45,25 @@ double ChromeAccessibilityDelegate::GetSavedScreenMagnifierScale() {
 
   return std::numeric_limits<double>::min();
 }
+
+void ChromeAccessibilityDelegate::DispatchAccessibilityEvent(
+    const ui::AXTreeID& tree_id,
+    const std::vector<ui::AXTreeUpdate>& updates,
+    const ui::AXEvent& event) {
+  ExtensionMsg_AccessibilityEventBundleParams event_bundle;
+  event_bundle.tree_id = tree_id;
+  for (const ui::AXTreeUpdate& update : updates)
+    event_bundle.updates.push_back(update);
+  event_bundle.events.push_back(event);
+  event_bundle.mouse_location = aura::Env::GetInstance()->last_mouse_location();
+
+  // Forward the tree updates and the event to the accessibility extension.
+  extensions::AutomationEventRouter::GetInstance()->DispatchAccessibilityEvents(
+      event_bundle);
+}
+
+void ChromeAccessibilityDelegate::DispatchTreeDestroyedEvent(
+    const ui::AXTreeID& tree_id) {
+  extensions::AutomationEventRouter::GetInstance()->DispatchTreeDestroyedEvent(
+      tree_id, nullptr /* browser_context */);
+}

chrome/browser/ui/ash/chrome_accessibility_delegate.h

@@ -20,6 +20,10 @@ class ChromeAccessibilityDelegate : public ash::AccessibilityDelegate {
   bool ShouldShowAccessibilityMenu() const override;
   void SaveScreenMagnifierScale(double scale) override;
   double GetSavedScreenMagnifierScale() override;
+  void DispatchAccessibilityEvent(const ui::AXTreeID& tree_id,
+                                  const std::vector<ui::AXTreeUpdate>& updates,
+                                  const ui::AXEvent& event) override;
+  void DispatchTreeDestroyedEvent(const ui::AXTreeID& tree_id) override;
 
  private:
   DISALLOW_COPY_AND_ASSIGN(ChromeAccessibilityDelegate);

chrome/browser/ui/aura/accessibility/DEPS

@@ -1,6 +1,7 @@
 specific_include_rules = {
   "automation_manager_aura\.cc": [
     # TODO(mash): Fix. https://crbug.com/756054
+    "+ash/accessibility/ax_host_service.h",
     "+ash/shell.h",
     "+ash/wm/window_util.h",
   ],