ozone: drm: Fix HardwareDisplayController use-after-free

ui/ozone/platform/drm/gpu/screen_manager.cc

 // Copyright 2014 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "ui/ozone/platform/drm/gpu/screen_manager.h"
 
 #include <xf86drmMode.h>
 
 #include "third_party/skia/include/core/SkCanvas.h"
 #include "ui/gfx/geometry/point.h"
@@ skipping 81 matching lines @@
       scoped_ptr<CrtcController>(new CrtcController(drm, crtc, connector))));
 }
 
 void ScreenManager::RemoveDisplayController(const scoped_refptr<DrmDevice>& drm,
                                             uint32_t crtc) {
   HardwareDisplayControllers::iterator it = FindDisplayController(drm, crtc);
   if (it != controllers_.end()) {
     bool is_mirrored = (*it)->IsMirrored();
     (*it)->RemoveCrtc(drm, crtc);
     if (!is_mirrored) {
+      controllers_.erase(it);
       UpdateControllerToWindowMapping();
-      controllers_.erase(it);
     }
   }
 }
 
 bool ScreenManager::ConfigureDisplayController(
     const scoped_refptr<DrmDevice>& drm,
     uint32_t crtc,
     uint32_t connector,
     const gfx::Point& origin,
     const drmModeModeInfo& mode) {
@@ skipping 213 matching lines @@
 DrmWindow* ScreenManager::FindWindowAt(const gfx::Rect& bounds) const {
   for (auto pair : window_map_) {
     if (pair.second->bounds() == bounds)
       return pair.second;
   }
 
   return nullptr;
 }
 
 }  // namespace ui