[Ozone-DRI] Make sure the display configuration is up-to-date on the GPU

ui/ozone/platform/dri/native_display_delegate_dri.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/dri/native_display_delegate_dri.h"
 
 #include "base/bind.h"
 #include "ui/display/types/native_display_observer.h"
 #include "ui/events/ozone/device/device_event.h"
 #include "ui/ozone/platform/dri/display_mode_dri.h"
@@ skipping 31 matching lines @@
   for (int i = 0; i < property->count_enums; ++i)
     if (name == property->enums[i].name)
       return i;
 
   NOTREACHED();
   return 0;
 }
 
 class DisplaySnapshotComparator {
  public:
-  DisplaySnapshotComparator(const DisplaySnapshotDri* snapshot)
-      : snapshot_(snapshot) {}
+  explicit DisplaySnapshotComparator(const DisplaySnapshotDri* snapshot)
+      : crtc_(snapshot->crtc()), connector_(snapshot->connector()) {}
+
+  DisplaySnapshotComparator(uint32_t crtc, uint32_t connector)
+      : crtc_(crtc), connector_(connector) {}
 
   bool operator()(const DisplaySnapshotDri* other) const {
-    if (snapshot_->connector() == other->connector() &&
-        snapshot_->crtc() == other->crtc())
-      return true;
-
-    return false;
+    return connector_ == other->connector() && crtc_ == other->crtc();
   }
 
  private:
-  const DisplaySnapshotDri* snapshot_;
+  uint32_t crtc_;
+  uint32_t connector_;
 };
 
 }  // namespace
 
 NativeDisplayDelegateDri::NativeDisplayDelegateDri(
     DriWrapper* dri,
     ScreenManager* screen_manager)
     : dri_(dri), screen_manager_(screen_manager) {
   // TODO(dnicoara): Remove when async display configuration is supported.
   screen_manager_->ForceInitializationOfPrimaryDisplay();
@@ skipping 58 matching lines @@
   for (size_t i = 0; i < cached_displays_.size(); ++i) {
     DisplaySnapshotDri* dri_output = cached_displays_[i];
     if (dri_output->dpms_property())
       dri_->SetProperty(dri_output->connector(),
                         dri_output->dpms_property()->prop_id, DRM_MODE_DPMS_ON);
   }
 }
 
 std::vector<DisplaySnapshot*> NativeDisplayDelegateDri::GetDisplays() {
   ScopedVector<DisplaySnapshotDri> old_displays(cached_displays_.Pass());
-  cached_modes_.clear();
+  ScopedVector<const DisplayMode> old_modes(cached_modes_.Pass());
 
   ScopedVector<HardwareDisplayControllerInfo> displays =
       GetAvailableDisplayControllerInfos(dri_->get_fd());
   for (size_t i = 0; i < displays.size(); ++i) {
     DisplaySnapshotDri* display = new DisplaySnapshotDri(
         dri_, displays[i]->connector(), displays[i]->crtc(), i);
+
+    // If the display exists make sure to sync up the new snapshot with the old
+    // one to keep the user configured details.
+    auto it = std::find_if(
+        old_displays.begin(), old_displays.end(),
+        DisplaySnapshotComparator(displays[i]->crtc()->crtc_id,
+                                  displays[i]->connector()->connector_id));
+    // Origin is only used within the platform code to keep track of the display
+    // location.
+    if (it != old_displays.end())
+      display->set_origin((*it)->origin());
+
     cached_displays_.push_back(display);
     cached_modes_.insert(cached_modes_.end(), display->modes().begin(),
                          display->modes().end());
   }
 
   NotifyScreenManager(cached_displays_.get(), old_displays.get());
 
   std::vector<DisplaySnapshot*> generic_displays(cached_displays_.begin(),
                                                  cached_displays_.end());
   return generic_displays;
@@ skipping 144 matching lines @@
         std::find_if(old_displays.begin(), old_displays.end(),
                      DisplaySnapshotComparator(new_displays[i]));
 
     if (it == old_displays.end())
       screen_manager_->AddDisplayController(dri_, new_displays[i]->crtc(),
                                             new_displays[i]->connector());
   }
 }
 
 }  // namespace ui