Make AccessibilityPrivateSendSyntheticKeyEventFunction mash compatible

- reuse ws::mojom::EventInjector
- follow up change will add a binding to chrome.accessibilityPrivate to send a synthesized mouse event (required for ChromeVox + VK support)
- removed last bits of ash deps from the file

Bug: 594887
Test: chromevox_tests (which makes extensive use of the chrome.accessibilityPrivate apis to send synthetic key events).
Change-Id: I1d4ce0703af526a747dd3b9db4422acb6b302307
Reviewed-on: https://chromium-review.googlesource.com/1250126Reviewed-by: James Cook <jamescook@chromium.org>
Commit-Queue: David Tseng <dtseng@chromium.org>
Cr-Commit-Position: refs/heads/master@{#595239}

chrome/browser/accessibility/DEPS

-specific_include_rules = {
-  "accessibility_extension_api\.cc": [
-    # TODO(mash): Replace with mojo API. http://crbug.com/594887
-    "+ash/accessibility/accessibility_focus_ring_controller.h",
-    "+ash/shell.h",
-  ],
-}

chrome/browser/accessibility/accessibility_extension_api.cc

@@ -38,12 +38,13 @@
 #include "ash/public/interfaces/accessibility_focus_ring_controller.mojom.h"
 #include "ash/public/interfaces/constants.mojom.h"
 #include "ash/public/interfaces/event_rewriter_controller.mojom.h"
-#include "ash/shell.h"
 #include "chrome/browser/chromeos/accessibility/accessibility_manager.h"
 #include "chrome/browser/chromeos/arc/accessibility/arc_accessibility_helper_bridge.h"
-#include "ui/aura/window_tree_host.h"
+#include "services/ws/public/mojom/constants.mojom.h"
+#include "services/ws/public/mojom/event_injector.mojom.h"
 #include "ui/base/ui_base_features.h"
-#include "ui/events/event_sink.h"
+#include "ui/display/display.h"
+#include "ui/display/screen.h"
 #endif
 
 namespace accessibility_private = extensions::api::accessibility_private;
@@ -233,12 +234,6 @@ AccessibilityPrivateSetNativeChromeVoxArcSupportForCurrentAppFunction::Run() {
 
 ExtensionFunction::ResponseAction
 AccessibilityPrivateSendSyntheticKeyEventFunction::Run() {
-  // TODO(crbug.com/876043): Mash support.
-  if (features::IsUsingWindowService()) {
-    NOTIMPLEMENTED();
-    return RespondNow(NoArguments());
-  }
-
   std::unique_ptr<accessibility_private::SendSyntheticKeyEvent::Params> params =
       accessibility_private::SendSyntheticKeyEvent::Params::Create(*args_);
   EXTENSION_FUNCTION_VALIDATE(params);
@@ -256,7 +251,8 @@ AccessibilityPrivateSendSyntheticKeyEventFunction::Run() {
       modifiers |= ui::EF_SHIFT_DOWN;
   }
 
-  ui::KeyEvent synthetic_key_event(
+  std::unique_ptr<ui::KeyEvent> synthetic_key_event =
+      std::make_unique<ui::KeyEvent>(
           key_data->type ==
                   accessibility_private::SYNTHETIC_KEYBOARD_EVENT_TYPE_KEYUP
               ? ui::ET_KEY_RELEASED
@@ -264,11 +260,14 @@ AccessibilityPrivateSendSyntheticKeyEventFunction::Run() {
           static_cast<ui::KeyboardCode>(key_data->key_code),
           static_cast<ui::DomCode>(0), modifiers);
 
-  // Only keyboard events, so dispatching to primary window suffices.
-  ui::EventSink* sink =
-      ash::Shell::GetPrimaryRootWindow()->GetHost()->event_sink();
-  if (sink->OnEventFromSource(&synthetic_key_event).dispatcher_destroyed)
-    return RespondNow(Error("Unable to dispatch key "));
+  ws::mojom::EventInjectorPtr event_injector_ptr;
+  content::ServiceManagerConnection* connection =
+      content::ServiceManagerConnection::GetForProcess();
+  connection->GetConnector()->BindInterface(ws::mojom::kServiceName,
+                                            &event_injector_ptr);
+  event_injector_ptr->InjectEventNoAck(
+      display::Screen::GetScreen()->GetPrimaryDisplay().id(),
+      std::move(synthetic_key_event));
 
   return RespondNow(NoArguments());
 }