views: makes WidgetFocusManager per Env on aura

As we may have two envs, WidgetFocusManager needs some context to know which
WidgetFocusManager to return.

BUG=874554
TEST=covered by tests

Change-Id: I397e14496351fc9839273aa7284c55cdb35555c8
Reviewed-on: https://chromium-review.googlesource.com/1212088Reviewed-by: Jun Mukai <mukai@chromium.org>
Commit-Queue: Scott Violet <sky@chromium.org>
Cr-Commit-Position: refs/heads/master@{#589593}

ash/accessibility/focus_ring_controller.cc

@@ -5,6 +5,7 @@
 #include "ash/accessibility/focus_ring_controller.h"
 
 #include "ash/accessibility/focus_ring_layer.h"
+#include "ash/shell.h"
 #include "ash/system/tray/actionable_view.h"
 #include "ash/system/tray/tray_background_view.h"
 #include "ash/wm/window_util.h"
@@ -28,13 +29,15 @@ void FocusRingController::SetVisible(bool visible) {
   visible_ = visible;
 
   if (visible_) {
-    views::WidgetFocusManager::GetInstance()->AddFocusChangeListener(this);
+    views::WidgetFocusManager::GetInstance(Shell::GetPrimaryRootWindow())
+        ->AddFocusChangeListener(this);
     aura::Window* active_window = wm::GetActiveWindow();
     if (active_window)
       SetWidget(views::Widget::GetWidgetForNativeWindow(active_window));
   } else {
-    views::WidgetFocusManager::GetInstance()->RemoveFocusChangeListener(this);
-    SetWidget(NULL);
+    views::WidgetFocusManager::GetInstance(Shell::GetPrimaryRootWindow())
+        ->RemoveFocusChangeListener(this);
+    SetWidget(nullptr);
   }
 }
 

ui/views/focus/widget_focus_manager.cc

@@ -4,17 +4,63 @@
 
 #include "ui/views/focus/widget_focus_manager.h"
 
-#include "base/memory/singleton.h"
+#include "base/supports_user_data.h"
+
+#if defined(USE_AURA)
+#include "ui/aura/env.h"
+#include "ui/aura/window.h"
+#endif
 
 namespace views {
 
+#if defined(USE_AURA)
+namespace {
+
+const char kWidgetFocusManagerKey[] = "WidgetFocusManager";
+
+}  // namespace
+
+class WidgetFocusManager::Owner : public base::SupportsUserData::Data {
+ public:
+  explicit Owner(std::unique_ptr<WidgetFocusManager> focus_manager)
+      : focus_manager_(std::move(focus_manager)) {}
+  ~Owner() override = default;
+
+  WidgetFocusManager* focus_manager() { return focus_manager_.get(); }
+
+ private:
+  std::unique_ptr<WidgetFocusManager> focus_manager_;
+
+  DISALLOW_COPY_AND_ASSIGN(Owner);
+};
+
+#endif
+
 // WidgetFocusManager ----------------------------------------------------------
 
 // static
-WidgetFocusManager* WidgetFocusManager::GetInstance() {
-  return base::Singleton<WidgetFocusManager>::get();
+WidgetFocusManager* WidgetFocusManager::GetInstance(gfx::NativeWindow context) {
+#if defined(USE_AURA)
+  // With aura there may be multiple Envs, in such a situation the
+  // WidgetFocusManager needs to be per Env.
+  aura::Env* env = context ? context->env() : aura::Env::GetInstance();
+  DCHECK(env);
+  Owner* owner = static_cast<Owner*>(env->GetUserData(kWidgetFocusManagerKey));
+  if (!owner) {
+    std::unique_ptr<Owner> owner_ptr =
+        std::make_unique<Owner>(base::WrapUnique(new WidgetFocusManager()));
+    owner = owner_ptr.get();
+    env->SetUserData(kWidgetFocusManagerKey, std::move(owner_ptr));
+  }
+  return owner->focus_manager();
+#else
+  static base::NoDestructor<WidgetFocusManager> instance;
+  return instance.get();
+#endif
 }
 
+WidgetFocusManager::~WidgetFocusManager() = default;
+
 void WidgetFocusManager::AddFocusChangeListener(
     WidgetFocusChangeListener* listener) {
   focus_change_listeners_.AddObserver(listener);
@@ -34,8 +80,6 @@ void WidgetFocusManager::OnNativeFocusChanged(gfx::NativeView focused_now) {
 
 WidgetFocusManager::WidgetFocusManager() : enabled_(true) {}
 
-WidgetFocusManager::~WidgetFocusManager() {}
-
 // AutoNativeNotificationDisabler ----------------------------------------------
 
 AutoNativeNotificationDisabler::AutoNativeNotificationDisabler() {

ui/views/focus/widget_focus_manager.h

@@ -6,14 +6,11 @@
 #define UI_VIEWS_FOCUS_WIDGET_FOCUS_MANAGER_H_
 
 #include "base/macros.h"
+#include "base/no_destructor.h"
 #include "base/observer_list.h"
 #include "ui/gfx/native_widget_types.h"
 #include "ui/views/views_export.h"
 
-namespace base {
-template <typename T> struct DefaultSingletonTraits;
-}
-
 namespace views {
 
 // This interface should be implemented by classes that want to be notified when
@@ -32,7 +29,9 @@ class WidgetFocusChangeListener {
 class VIEWS_EXPORT WidgetFocusManager {
  public:
   // Returns the singleton instance.
-  static WidgetFocusManager* GetInstance();
+  static WidgetFocusManager* GetInstance(gfx::NativeWindow context = nullptr);
+
+  ~WidgetFocusManager();
 
   // Adds/removes a WidgetFocusChangeListener |listener| to the set of
   // active listeners.
@@ -50,10 +49,10 @@ class VIEWS_EXPORT WidgetFocusManager {
   void DisableNotifications() { enabled_ = false; }
 
  private:
-  friend struct base::DefaultSingletonTraits<WidgetFocusManager>;
+  class Owner;
+  friend class base::NoDestructor<WidgetFocusManager>;
 
   WidgetFocusManager();
-  ~WidgetFocusManager();
 
   base::ObserverList<WidgetFocusChangeListener>::Unchecked
       focus_change_listeners_;

ui/views/widget/widget.cc

@@ -1058,11 +1058,13 @@ bool Widget::OnNativeWidgetActivationChanged(bool active) {
 }
 
 void Widget::OnNativeFocus() {
-  WidgetFocusManager::GetInstance()->OnNativeFocusChanged(GetNativeView());
+  WidgetFocusManager::GetInstance(GetNativeWindow())
+      ->OnNativeFocusChanged(GetNativeView());
 }
 
 void Widget::OnNativeBlur() {
-  WidgetFocusManager::GetInstance()->OnNativeFocusChanged(nullptr);
+  WidgetFocusManager::GetInstance(GetNativeWindow())
+      ->OnNativeFocusChanged(nullptr);
 }
 
 void Widget::OnNativeWidgetVisibilityChanging(bool visible) {