Revert "Makes magnifier observe AXEventManager for focus changes"

This reverts commit 217c3a78.

Reason for revert: <INSERT REASONING HERE>
crbug.com/1016132

Original change's description:
> Makes magnifier observe AXEventManager for focus changes
> 
> Bug: 865575
> Change-Id: I8d8328a459d7621d6fc0a0d65e0f24f788b9767f
> Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/1852414
> Commit-Queue: David Tseng <dtseng@chromium.org>
> Reviewed-by: Dominic Mazzoni <dmazzoni@chromium.org>
> Cr-Commit-Position: refs/heads/master@{#704854}

TBR=dmazzoni@chromium.org,dtseng@chromium.org

# Not skipping CQ checks because original CL landed > 1 day ago.

Bug: 865575,1016132
Change-Id: Id77035499da1e2b36c1216b622eb8f341449406b
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/1875449Reviewed-by: David Tseng <dtseng@chromium.org>
Commit-Queue: David Tseng <dtseng@chromium.org>
Cr-Commit-Position: refs/heads/master@{#708525}

chrome/browser/chromeos/accessibility/magnification_manager.cc

@@ -25,7 +25,6 @@
 #include "content/public/browser/notification_source.h"
 #include "content/public/common/service_manager_connection.h"
 #include "services/service_manager/public/cpp/connector.h"
-#include "ui/views/accessibility/ax_event_manager.h"
 
 namespace chromeos {
 
@@ -99,18 +98,6 @@ void MagnificationManager::OnProfileWillBeDestroyed(Profile* profile) {
   SetProfile(nullptr);
 }
 
-void MagnificationManager::OnViewEvent(views::View* view,
-                                       ax::mojom::Event event_type) {
-  if (!fullscreen_magnifier_enabled_ && !IsDockedMagnifierEnabled())
-    return;
-
-  if (event_type != ax::mojom::Event::kFocus &&
-      event_type != ax::mojom::Event::kSelection)
-    return;
-
-  HandleFocusChanged(view->GetBoundsInScreen(), false);
-}
-
 void MagnificationManager::SetProfileForTest(Profile* profile) {
   SetProfile(profile);
 }
@@ -123,12 +110,10 @@ MagnificationManager::MagnificationManager() {
   registrar_.Add(this, content::NOTIFICATION_FOCUS_CHANGED_IN_PAGE,
                  content::NotificationService::AllSources());
   user_manager::UserManager::Get()->AddSessionStateObserver(this);
-  views::AXEventManager::Get()->AddObserver(this);
 }
 
 MagnificationManager::~MagnificationManager() {
   CHECK(this == g_magnification_manager);
-  views::AXEventManager::Get()->RemoveObserver(this);
   user_manager::UserManager::Get()->RemoveSessionStateObserver(this);
 }
 
@@ -296,22 +281,17 @@ void MagnificationManager::HandleFocusChangedInPage(
   if (node_details->is_editable_node)
     return;
 
-  HandleFocusChanged(node_details->node_bounds_in_screen,
-                     node_details->is_editable_node);
-}
-
-void MagnificationManager::HandleFocusChanged(const gfx::Rect& bounds_in_screen,
-                                              bool is_editable) {
+  const gfx::Rect& bounds_in_screen = node_details->node_bounds_in_screen;
   if (bounds_in_screen.IsEmpty())
     return;
 
   // Fullscreen magnifier and docked magnifier are mutually exclusive.
   if (fullscreen_magnifier_enabled_) {
     ash::Shell::Get()->magnification_controller()->HandleFocusedNodeChanged(
-        is_editable, bounds_in_screen);
+        node_details->is_editable_node, node_details->node_bounds_in_screen);
     return;
   }
-  DCHECK(IsDockedMagnifierEnabled());
+  DCHECK(docked_magnifier_enabled);
   ash::DockedMagnifierController::Get()->CenterOnPoint(
       bounds_in_screen.CenterPoint());
 }

chrome/browser/chromeos/accessibility/magnification_manager.h

@@ -13,7 +13,6 @@
 #include "components/user_manager/user_manager.h"
 #include "content/public/browser/notification_observer.h"
 #include "content/public/browser/notification_registrar.h"
-#include "ui/views/accessibility/ax_event_observer.h"
 
 class PrefChangeRegistrar;
 
@@ -34,8 +33,7 @@ namespace chromeos {
 class MagnificationManager
     : public content::NotificationObserver,
       public user_manager::UserManager::UserSessionStateObserver,
-      public ProfileObserver,
-      public views::AXEventObserver {
+      public ProfileObserver {
  public:
   // Creates an instance of MagnificationManager. This should be called once.
   static void Initialize();
@@ -67,9 +65,6 @@ class MagnificationManager
   // ProfileObserver:
   void OnProfileWillBeDestroyed(Profile* profile) override;
 
-  // views::AXEventObserver:
-  void OnViewEvent(views::View* view, ax::mojom::Event event_type) override;
-
   void SetProfileForTest(Profile* profile);
 
  private:
@@ -96,9 +91,6 @@ class MagnificationManager
   // Called when received content::NOTIFICATION_FOCUS_CHANGED_IN_PAGE.
   void HandleFocusChangedInPage(const content::NotificationDetails& details);
 
-  // Called in response to AXEventObserver.
-  void HandleFocusChanged(const gfx::Rect& bounds_in_screen, bool is_editable);
-
   Profile* profile_ = nullptr;
   ScopedObserver<Profile, ProfileObserver> profile_observer_{this};