Don't dispatch event after shutdown on AshWTHUnified

in the same way as AshWTHX11/Ozone

Fixed minor error introduced when cleaning up CL

BUG=365662
TEST=UnifiedDesktopBasic will pass with real offscreen output surface

Review URL: https://codereview.chromium.org/1113493002

Cr-Commit-Position: refs/heads/master@{#327333}

ash/display/display_controller.cc

@@ -631,7 +631,9 @@ bool DisplayController::UpdateWorkAreaOfDisplayNearestWindow(
 }
 
 void DisplayController::OnDisplayAdded(const gfx::Display& display) {
-  if (GetDisplayManager()->IsInUnifiedMode()) {
+#if defined(OS_CHROMEOS)
+  if (GetDisplayManager()->default_multi_display_mode() ==
+      DisplayManager::UNIFIED) {
     if (primary_display_id == gfx::Display::kInvalidDisplayID)
       primary_display_id = display.id();
     AshWindowTreeHost* ash_host =
@@ -642,13 +644,22 @@ void DisplayController::OnDisplayAdded(const gfx::Display& display) {
       AshWindowTreeHost* to_delete = primary_tree_host_for_replace_;
       primary_tree_host_for_replace_ = nullptr;
       DeleteHost(to_delete);
+#ifndef NDEBUG
+      auto iter = std::find_if(
+          window_tree_hosts_.begin(), window_tree_hosts_.end(),
+          [to_delete](const std::pair<int64, AshWindowTreeHost*>& pair) {
+            return pair.second == to_delete;
+          });
+      DCHECK(iter == window_tree_hosts_.end());
+#endif
       // the host has already been removed from the window_tree_host_.
     }
-  }
-  // TODO(oshima): It should be possible to consolidate logic for
-  // unified and non unified, but I'm keeping them separated to minimize
-  // the risk in M44. I'll consolidate this in M45.
-  else if (primary_tree_host_for_replace_) {
+  } else
+#endif
+      // TODO(oshima): It should be possible to consolidate logic for
+      // unified and non unified, but I'm keeping them separated to minimize
+      // the risk in M44. I'll consolidate this in M45.
+      if (primary_tree_host_for_replace_) {
     DCHECK(window_tree_hosts_.empty());
     primary_display_id = display.id();
     window_tree_hosts_[display.id()] = primary_tree_host_for_replace_;

ash/display/mirror_window_controller.cc

@@ -145,7 +145,7 @@ void MirrorWindowController::UpdateWindow(
       mirror_window->SetBounds(host->window()->bounds());
       mirror_window->Show();
       if (reflector_) {
-        // TODO(oshima): Enable this once reflect change is landed.
+        // TODO(oshima): Enable this once reflector change is landed.
         // reflector_->AddMirroringLayer(mirror_window->layer());
       } else {
         reflector_ =
@@ -267,7 +267,9 @@ void MirrorWindowController::CloseAndDeleteHost(MirroringHostInfo* host_info) {
 
   host->RemoveObserver(Shell::GetInstance()->display_controller());
   host->RemoveObserver(this);
-  // reflector_->RemoveMirroringLayer(host_info->mirror_window->layer());
+  host_info->ash_host->PrepareForShutdown();
+  // TODO(oshima): Enable this once reflector change is landed.
+  // reflector_->RemovedMirroringLayer(mirror_window->layer());
   delete host_info;
 }
 

ash/host/ash_window_tree_host_unified.cc

@@ -10,6 +10,7 @@
 #include "ui/aura/window_targeter.h"
 #include "ui/compositor/compositor.h"
 #include "ui/events/event_processor.h"
+#include "ui/events/null_event_targeter.h"
 #include "ui/gfx/geometry/insets.h"
 
 namespace ash {
@@ -56,6 +57,9 @@ AshWindowTreeHostUnified::~AshWindowTreeHostUnified() {
 }
 
 void AshWindowTreeHostUnified::PrepareForShutdown() {
+  window()->SetEventTargeter(
+      scoped_ptr<ui::EventTargeter>(new ui::NullEventTargeter));
+
   for (auto host : mirroring_hosts_)
     host->PrepareForShutdown();
 }