[1.5/2][Ozone-Drm] Keep track of display origin

ui/ozone/platform/drm/gpu/drm_gpu_display_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/drm_gpu_display_manager.h"
 
 #include "ui/display/types/gamma_ramp_rgb_entry.h"
 #include "ui/ozone/common/display_util.h"
 #include "ui/ozone/platform/drm/common/drm_util.h"
 #include "ui/ozone/platform/drm/gpu/drm_device.h"
@@ skipping 37 matching lines @@
         mode_params.refresh_rate == params.refresh_rate &&
         mode_params.is_interlaced == params.is_interlaced) {
       *mode = m;
       return true;
     }
   }
 
   return false;
 }
 
-std::vector<drmModeModeInfo> GetDrmModeVector(drmModeConnector* connector) {
-  std::vector<drmModeModeInfo> modes;
-  for (int i = 0; i < connector->count_modes; ++i)
-    modes.push_back(connector->modes[i]);
-
-  return modes;
-}
-
 }  // namespace
 
 DrmGpuDisplayManager::DrmGpuDisplayManager(ScreenManager* screen_manager,
                                            DrmDeviceManager* drm_device_manager)
     : screen_manager_(screen_manager), drm_device_manager_(drm_device_manager) {
 }
 
 DrmGpuDisplayManager::~DrmGpuDisplayManager() {
 }
 
 std::vector<DisplaySnapshot_Params> DrmGpuDisplayManager::GetDisplays() {
   ScopedVector<DrmDisplay> old_displays(displays_.Pass());
   std::vector<DisplaySnapshot_Params> params_list;
 
   const DrmDeviceVector& devices = drm_device_manager_->GetDrmDevices();
   // Unique identifier used to create the display id.
   size_t index = 0;
   for (const auto& drm : devices) {
     ScopedVector<HardwareDisplayControllerInfo> display_infos =
         GetAvailableDisplayControllerInfos(drm->get_fd());
     for (auto* display_info : display_infos) {
-      DisplaySnapshot_Params params =
-          CreateDisplaySnapshotParams(display_info, drm->get_fd(), index++);
-      params_list.push_back(params);
+      auto it = std::find_if(
+          old_displays.begin(), old_displays.end(),
+          DisplayComparator(drm, display_info->crtc()->crtc_id,
+                            display_info->connector()->connector_id));
+      if (it != old_displays.end()) {
+        displays_.push_back(*it);
+        old_displays.weak_erase(it);
+      } else {
+        displays_.push_back(new DrmDisplay(screen_manager_, drm));
+      }
 
-      displays_.push_back(
-          new DrmDisplay(screen_manager_, params.display_id, drm,
-                         display_info->crtc()->crtc_id,
-                         display_info->connector()->connector_id,
-                         GetDrmModeVector(display_info->connector())));
+      params_list.push_back(displays_.back()->Update(display_info, index++));
     }
   }
 
   NotifyScreenManager(displays_.get(), old_displays.get());
   return params_list;
 }
 
 bool DrmGpuDisplayManager::TakeDisplayControl() {
   const DrmDeviceVector& devices = drm_device_manager_->GetDrmDevices();
   for (const auto& drm : devices) {
@@ skipping 123 matching lines @@
 
     if (it == old_displays.end()) {
       screen_manager_->AddDisplayController(new_displays[i]->drm(),
                                             new_displays[i]->crtc(),
                                             new_displays[i]->connector());
     }
   }
 }
 
 }  // namespace ui