Fix expected PlacementList sort order.

ui/display/display_layout.cc

 // Copyright 2016 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/display/display_layout.h"
 
 #include <algorithm>
 #include <map>
 #include <set>
 #include <sstream>
@@ skipping 21 matching lines @@
 const int kMaxValidOffset = 10000;
 
 bool IsIdInList(int64_t id, const DisplayIdList& list) {
   const auto iter =
       std::find_if(list.begin(), list.end(),
                    [id](int64_t display_id) { return display_id == id; });
   return iter != list.end();
 }
 
 bool ComparePlacements(const DisplayPlacement& d1, const DisplayPlacement& d2) {
-  return d1.display_id < d2.display_id;
+  return CompareDisplayIds(d1.display_id, d2.display_id);
 }
 
 // Extracts the displays IDs list from the displays list.
 DisplayIdList DisplayListToDisplayIdList(const Displays& displays) {
   DisplayIdList list;
   for (const auto& display : displays)
     list.emplace_back(display.id());
 
   return list;
 }
@@ skipping 475 matching lines @@
                << " is not in the id list.";
     return false;
   }
 
   // Unified mode, or mirror mode switched from unified mode,
   // may not have the placement yet.
   if (layout.placement_list.size() == 0u)
     return true;
 
   bool has_primary_as_parent = false;
-  int64_t prev_id = std::numeric_limits<int64_t>::min();
+  // The placement list must be sorted by the first 8 bits of the display IDs.
+  int64_t prev_id = std::numeric_limits<int8_t>::min();
   for (const auto& placement : layout.placement_list) {
     // Placements are sorted by display_id.
-    if (prev_id >= placement.display_id) {
-      LOG(ERROR) << "PlacementList must be sorted by display_id";
+    if (prev_id >= (placement.display_id & 0xFF)) {
+      LOG(ERROR) << "PlacementList must be sorted by first 8 bits of"
+                 << " display_id ";
       return false;
     }
-    prev_id = placement.display_id;
+    prev_id = (placement.display_id & 0xFF);
     if (placement.display_id == kInvalidDisplayId) {
       LOG(ERROR) << "display_id is not initialized";
       return false;
     }
     if (placement.parent_display_id == kInvalidDisplayId) {
       LOG(ERROR) << "display_parent_id is not initialized";
       return false;
     }
     if (placement.display_id == placement.parent_display_id) {
       LOG(ERROR) << "display_id must not be same as parent_display_id";
@@ skipping 130 matching lines @@
 
   gfx::Insets insets = target_display->GetWorkAreaInsets();
   target_display->set_bounds(
       gfx::Rect(new_target_origin, target_bounds.size()));
   target_display->UpdateWorkAreaFromInsets(insets);
 
   return old_bounds != target_display->bounds();
 }
 
 }  // namespace display