Disable magnification palette tool unless experimental palette features are enabled.

ash/common/system/chromeos/palette/palette_tool.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 "ash/common/system/chromeos/palette/palette_tool.h"
 
 #include "ash/common/system/chromeos/palette/palette_tool_manager.h"
+#include "ash/common/system/chromeos/palette/palette_utils.h"
 #include "ash/common/system/chromeos/palette/tools/capture_region_action.h"
 #include "ash/common/system/chromeos/palette/tools/capture_screen_action.h"
 #include "ash/common/system/chromeos/palette/tools/create_note_action.h"
 #include "ash/common/system/chromeos/palette/tools/magnifier_mode.h"
 #include "base/memory/ptr_util.h"
 #include "ui/gfx/vector_icons_public.h"
 
 namespace ash {
 
 // static
 void PaletteTool::RegisterToolInstances(PaletteToolManager* tool_manager) {
   tool_manager->AddTool(base::MakeUnique<CaptureRegionAction>(tool_manager));
   tool_manager->AddTool(base::MakeUnique<CaptureScreenAction>(tool_manager));
   tool_manager->AddTool(base::MakeUnique<CreateNoteAction>(tool_manager));
-  tool_manager->AddTool(base::MakeUnique<MagnifierMode>(tool_manager));
+  if (ArePaletteExperimentalFeaturesEnabled())
+    tool_manager->AddTool(base::MakeUnique<MagnifierMode>(tool_manager));
 }
 
 PaletteTool::PaletteTool(Delegate* delegate) : delegate_(delegate) {}
 
 PaletteTool::~PaletteTool() {}
 
 void PaletteTool::OnEnable() {
   enabled_ = true;
 }
 
 void PaletteTool::OnDisable() {
   enabled_ = false;
 }
 
 gfx::VectorIconId PaletteTool::GetActiveTrayIcon() {
   return gfx::VectorIconId::VECTOR_ICON_NONE;
 }
 
 }  // namespace ash