Remove ability to switch to pre-MD UI from about:flags.

ui/base/material_design/material_design_controller.cc

 // Copyright 2015 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/base/material_design/material_design_controller.h"
 
 #include <string>
 
 #include "base/command_line.h"
 #include "base/logging.h"
@@ skipping 12 matching lines @@
 #include "ui/events/ozone/evdev/event_device_info.h"
 #endif  // defined(USE_OZONE)
 
 #endif  // defined(OS_CHROMEOS)
 
 namespace ui {
 
 bool MaterialDesignController::is_mode_initialized_ = false;
 
 MaterialDesignController::Mode MaterialDesignController::mode_ =
-    MaterialDesignController::NON_MATERIAL;
+    MaterialDesignController::MATERIAL_NORMAL;
 
 bool MaterialDesignController::include_secondary_ui_ = false;
 
 // static
 void MaterialDesignController::Initialize() {
   TRACE_EVENT0("startup", "MaterialDesignController::InitializeMode");
   CHECK(!is_mode_initialized_);
   const std::string switch_value =
       base::CommandLine::ForCurrentProcess()->GetSwitchValueASCII(
           switches::kTopChromeMD);
 
   if (switch_value == switches::kTopChromeMDMaterial) {
     SetMode(MATERIAL_NORMAL);
   } else if (switch_value == switches::kTopChromeMDMaterialHybrid) {
     SetMode(MATERIAL_HYBRID);
-  } else if (switch_value == switches::kTopChromeMDNonMaterial) {
-    SetMode(NON_MATERIAL);
   } else {
     if (!switch_value.empty()) {
       LOG(ERROR) << "Invalid value='" << switch_value
                  << "' for command line switch '" << switches::kTopChromeMD
                  << "'.";
     }
     SetMode(DefaultMode());
   }
 
   include_secondary_ui_ = base::CommandLine::ForCurrentProcess()->HasSwitch(
       switches::kExtendMdToSecondaryUi);
 }
 
 // static
 MaterialDesignController::Mode MaterialDesignController::GetMode() {
   CHECK(is_mode_initialized_);
   return mode_;
 }
 
 // static
 bool MaterialDesignController::IsModeMaterial() {
-  return GetMode() == MATERIAL_NORMAL || GetMode() == MATERIAL_HYBRID;
+  return true;
 }
 
 // static
 bool MaterialDesignController::IsSecondaryUiMaterial() {
   return IsModeMaterial() && include_secondary_ui_;
 }
 
 // static
 MaterialDesignController::Mode MaterialDesignController::DefaultMode() {
 #if defined(OS_CHROMEOS)
@@ skipping 36 matching lines @@
   is_mode_initialized_ = false;
 }
 
 // static
 void MaterialDesignController::SetMode(MaterialDesignController::Mode mode) {
   mode_ = mode;
   is_mode_initialized_ = true;
 }
 
 }  // namespace ui