Specify a default display UI scale to reset the zoom to

ash/display/display_manager.cc

 // Copyright (c) 2012 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 "ash/display/display_manager.h"
 
 #include <algorithm>
 #include <cmath>
 #include <limits>
 #include <map>
@@ skipping 96 matching lines @@
 
 gfx::Size GetMaxNativeSize(const display::ManagedDisplayInfo& info) {
   gfx::Size size;
   for (auto& mode : info.display_modes()) {
     if (mode->size().GetArea() > size.GetArea())
       size = mode->size();
   }
   return size;
 }
 
-scoped_refptr<display::ManagedDisplayMode> GetDisplayModeForUIScale(
-    const display::ManagedDisplayInfo& info,
-    float ui_scale) {
-  const display::ManagedDisplayInfo::ManagedDisplayModeList& modes =
-      info.display_modes();
-  auto iter = std::find_if(
-      modes.begin(), modes.end(),
-      [ui_scale](const scoped_refptr<display::ManagedDisplayMode>& mode) {
-        return mode->ui_scale() == ui_scale;
-      });
+scoped_refptr<display::ManagedDisplayMode> GetDefaultDisplayMode(
+    const display::ManagedDisplayInfo& info) {
+  const auto& modes = info.display_modes();
+  auto iter =
+      std::find_if(modes.begin(), modes.end(),
+                   [](const scoped_refptr<display::ManagedDisplayMode>& mode) {
+                     return mode->is_default();
+                   });
+
   if (iter == modes.end())
     return scoped_refptr<display::ManagedDisplayMode>();
   return *iter;
 }
 
 }  // namespace
 
 using std::string;
 using std::vector;
 
@@ skipping 953 matching lines @@
     if (!IsActiveDisplayId(display_info.id()) ||
         !display::Display::IsInternalDisplayId(display_info.id())) {
       return false;
     }
     mode = GetDisplayModeForNextUIScale(display_info, up);
   }
 
   return mode ? SetDisplayMode(display_id, mode) : false;
 }
 
-bool DisplayManager::SetDisplayUIScale(int64_t id, float ui_scale) {
-  if (!IsActiveDisplayId(id) || !display::Display::IsInternalDisplayId(id)) {
+bool DisplayManager::ResetDisplayToDefaultMode(int64_t id) {
+  if (!IsActiveDisplayId(id) || !display::Display::IsInternalDisplayId(id))
     return false;
-  }
+
   const display::ManagedDisplayInfo& info = GetDisplayInfo(id);
+  scoped_refptr<display::ManagedDisplayMode> mode = GetDefaultDisplayMode(info);
 
-  scoped_refptr<display::ManagedDisplayMode> mode =
-      GetDisplayModeForUIScale(info, ui_scale);
-  if (!mode)
-    return false;
-  return SetDisplayMode(id, mode);
+  return mode ? SetDisplayMode(id, mode) : false;
 }
 
 void DisplayManager::ResetInternalDisplayZoom() {
   if (IsInUnifiedMode()) {
     const display::ManagedDisplayInfo& display_info =
         GetDisplayInfo(DisplayManager::kUnifiedDisplayId);
     const display::ManagedDisplayInfo::ManagedDisplayModeList& modes =
         display_info.display_modes();
     auto iter = std::find_if(
         modes.begin(), modes.end(),
         [](const scoped_refptr<display::ManagedDisplayMode>& mode) {
           return mode->native();
         });
     SetDisplayMode(kUnifiedDisplayId, *iter);
   } else {
-    SetDisplayUIScale(GetDisplayIdForUIScaling(), 1.0f);
+    ResetDisplayToDefaultMode(GetDisplayIdForUIScaling());
   }
 }
 
 void DisplayManager::CreateSoftwareMirroringDisplayInfo(
     DisplayInfoList* display_info_list) {
   // Use the internal display or 1st as the mirror source, then scale
   // the root window so that it matches the external display's
   // resolution. This is necessary in order for scaling to work while
   // mirrored.
   switch (multi_display_mode_) {
@@ skipping 296 matching lines @@
 
 const display::Display& DisplayManager::GetSecondaryDisplay() const {
   CHECK_LE(2U, GetNumDisplays());
   return GetDisplayAt(0).id() ==
                  display::Screen::GetScreen()->GetPrimaryDisplay().id()
              ? GetDisplayAt(1)
              : GetDisplayAt(0);
 }
 
 }  // namespace ash