Convert <select> popup observer to ui::EventObserver

This is needed for it to observe clicks outside the browser window
(e.g. on the desktop) under SingleProcessMash on Chrome OS.

Bug: 896948
Test: existing content_unittests
Change-Id: I8cdfa78f934255bde7e23a3964990e418717eb54
Reviewed-on: https://chromium-review.googlesource.com/c/1292810Reviewed-by: Sadrul Chowdhury <sadrul@chromium.org>
Reviewed-by: Michael Wasserman <msw@chromium.org>
Commit-Queue: James Cook <jamescook@chromium.org>
Cr-Commit-Position: refs/heads/master@{#601710}

content/browser/renderer_host/render_widget_host_view_aura.cc

@@ -88,6 +88,7 @@
 #include "ui/events/blink/did_overscroll_params.h"
 #include "ui/events/blink/web_input_event.h"
 #include "ui/events/event.h"
+#include "ui/events/event_observer.h"
 #include "ui/events/event_utils.h"
 #include "ui/events/gesture_detection/gesture_configuration.h"
 #include "ui/events/gestures/gesture_recognizer.h"
@@ -194,45 +195,41 @@ class WinScreenKeyboardObserver
 
 // We need to watch for mouse events outside a Web Popup or its parent
 // and dismiss the popup for certain events.
-class RenderWidgetHostViewAura::EventFilterForPopupExit
-    : public ui::EventHandler {
+class RenderWidgetHostViewAura::EventObserverForPopupExit
+    : public ui::EventObserver {
  public:
-  explicit EventFilterForPopupExit(RenderWidgetHostViewAura* rwhva)
+  explicit EventObserverForPopupExit(RenderWidgetHostViewAura* rwhva)
       : rwhva_(rwhva) {
-    DCHECK(rwhva_);
-    aura::Env::GetInstance()->AddPreTargetHandler(this);
+    aura::Env* env = aura::Env::GetInstance();
+    env->AddEventObserver(this, env,
+                          {ui::ET_MOUSE_PRESSED, ui::ET_TOUCH_PRESSED});
   }
 
-  ~EventFilterForPopupExit() override {
-    aura::Env::GetInstance()->RemovePreTargetHandler(this);
+  ~EventObserverForPopupExit() override {
+    aura::Env::GetInstance()->RemoveEventObserver(this);
   }
 
-  // Overridden from ui::EventHandler
-  void OnMouseEvent(ui::MouseEvent* event) override {
-    rwhva_->ApplyEventFilterForPopupExit(event);
-  }
-
-  void OnTouchEvent(ui::TouchEvent* event) override {
-    rwhva_->ApplyEventFilterForPopupExit(event);
+  // ui::EventObserver:
+  void OnEvent(const ui::Event& event) override {
+    rwhva_->ApplyEventObserverForPopupExit(*event.AsLocatedEvent());
   }
 
  private:
   RenderWidgetHostViewAura* rwhva_;
 
-  DISALLOW_COPY_AND_ASSIGN(EventFilterForPopupExit);
+  DISALLOW_COPY_AND_ASSIGN(EventObserverForPopupExit);
 };
 
-void RenderWidgetHostViewAura::ApplyEventFilterForPopupExit(
-    ui::LocatedEvent* event) {
-  if (in_shutdown_ || is_fullscreen_ || !event->target())
-    return;
+void RenderWidgetHostViewAura::ApplyEventObserverForPopupExit(
+    const ui::LocatedEvent& event) {
+  DCHECK(event.type() == ui::ET_MOUSE_PRESSED ||
+         event.type() == ui::ET_TOUCH_PRESSED);
 
-  if (event->type() != ui::ET_MOUSE_PRESSED &&
-      event->type() != ui::ET_TOUCH_PRESSED) {
+  if (in_shutdown_ || is_fullscreen_)
     return;
-  }
 
-  aura::Window* target = static_cast<aura::Window*>(event->target());
+  // |target| may be null.
+  aura::Window* target = static_cast<aura::Window*>(event.target());
   if (target != window_ &&
       (!popup_parent_host_view_ ||
        target != popup_parent_host_view_->window_)) {
@@ -466,7 +463,8 @@ void RenderWidgetHostViewAura::InitAsPopup(
   if (NeedsMouseCapture())
     window_->SetCapture();
 
-  event_filter_for_popup_exit_.reset(new EventFilterForPopupExit(this));
+  event_observer_for_popup_exit_ =
+      std::make_unique<EventObserverForPopupExit>(this);
 
   device_scale_factor_ = GetDeviceScaleFactor();
 }
@@ -1953,7 +1951,7 @@ RenderWidgetHostViewAura::~RenderWidgetHostViewAura() {
            popup_child_host_view_->popup_parent_host_view_ == this);
     popup_child_host_view_->popup_parent_host_view_ = nullptr;
   }
-  event_filter_for_popup_exit_.reset();
+  event_observer_for_popup_exit_.reset();
 
 #if defined(OS_WIN)
   // The LegacyRenderWidgetHostHWND window should have been destroyed in

content/browser/renderer_host/render_widget_host_view_aura.h

@@ -532,7 +532,7 @@ class CONTENT_EXPORT RenderWidgetHostViewAura
 
   // Dismisses a Web Popup on a mouse or touch press outside the popup and its
   // parent.
-  void ApplyEventFilterForPopupExit(ui::LocatedEvent* event);
+  void ApplyEventObserverForPopupExit(const ui::LocatedEvent& event);
 
   // Converts |rect| from screen coordinate to window coordinate.
   gfx::Rect ConvertRectFromScreen(const gfx::Rect& rect) const;
@@ -586,9 +586,8 @@ class CONTENT_EXPORT RenderWidgetHostViewAura
   // Our child popup host. NULL if we do not have a child popup.
   RenderWidgetHostViewAura* popup_child_host_view_;
 
-  class EventFilterForPopupExit;
-  friend class EventFilterForPopupExit;
-  std::unique_ptr<ui::EventHandler> event_filter_for_popup_exit_;
+  class EventObserverForPopupExit;
+  std::unique_ptr<EventObserverForPopupExit> event_observer_for_popup_exit_;
 
   // True when content is being loaded. Used to show an hourglass cursor.
   bool is_loading_;