Enable MD by default on Windows for Canary/Dev and local builds.

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 <string>
 
 #include "base/command_line.h"
 #include "base/logging.h"
+#include "base/metrics/field_trial.h"
 #include "base/trace_event/trace_event.h"
 #include "ui/base/material_design/material_design_controller.h"
 #include "ui/base/ui_base_switches.h"
 
 #if defined(OS_CHROMEOS)
 #include "ui/base/touch/touch_device.h"
 #include "ui/events/devices/device_data_manager.h"
 
 #if defined(USE_OZONE)
 #include <fcntl.h>
 
 #include "base/files/file_enumerator.h"
 #include "base/threading/thread_restrictions.h"
 #include "ui/events/ozone/evdev/event_device_info.h"
 #endif  // defined(USE_OZONE)
 
 #endif  // defined(OS_CHROMEOS)
 
 namespace ui {
 
+// static
 bool MaterialDesignController::is_mode_initialized_ = false;
-
 MaterialDesignController::Mode MaterialDesignController::mode_ =
     MaterialDesignController::NON_MATERIAL;
 
 bool MaterialDesignController::include_secondary_ui_ = false;
 
 // static
 void MaterialDesignController::Initialize() {
+  InitializeWithDefaultMode(DefaultMode());
+}
+
+// static
+void MaterialDesignController::InitializeWithDefaultMode(Mode mode) {
   TRACE_EVENT0("startup", "MaterialDesignController::InitializeMode");
   CHECK(!is_mode_initialized_);
 #if !defined(ENABLE_TOPCHROME_MD)
   SetMode(NON_MATERIAL);
 #else
   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());
+
+    // The field trial value, if any, overrides the provided default mode.
+    constexpr char kMaterialDesignModeFieldTrialName[] = "MaterialDesignMode";
+    constexpr char kNonMaterialGroupName[] = "NonMaterial";
+    constexpr char kMaterialNormalGroupName[] = "MaterialNormal";
+    constexpr char kMaterialHybridGroupName[] = "MaterialHybrid";
+    const std::string group =
+        base::FieldTrialList::FindFullName(kMaterialDesignModeFieldTrialName);
+    if (group == kNonMaterialGroupName)
+      mode = NON_MATERIAL;
+    else if (group == kMaterialNormalGroupName)
+      mode = MATERIAL_NORMAL;
+    else if (group == kMaterialHybridGroupName)
+      mode = MATERIAL_HYBRID;
+
+    SetMode(mode);
   }
 
   include_secondary_ui_ = base::CommandLine::ForCurrentProcess()->HasSwitch(
       switches::kExtendMdToSecondaryUi);
 #endif  // !defined(ENABLE_TOPCHROME_MD)
 }
 
 // static
 MaterialDesignController::Mode MaterialDesignController::GetMode() {
   CHECK(is_mode_initialized_);
   return mode_;
 }
 
 // static
 bool MaterialDesignController::IsModeMaterial() {
   return GetMode() == MATERIAL_NORMAL || GetMode() == MATERIAL_HYBRID;
 }
 
 // static
 bool MaterialDesignController::IsSecondaryUiMaterial() {
   return IsModeMaterial() && include_secondary_ui_;
 }
 
 // static
+void MaterialDesignController::Uninitialize() {
+  is_mode_initialized_ = false;
+}
+
+// static
+void MaterialDesignController::SetMode(MaterialDesignController::Mode mode) {
+  mode_ = mode;
+  is_mode_initialized_ = true;
+}
+
+// static
 MaterialDesignController::Mode MaterialDesignController::DefaultMode() {
 #if defined(OS_CHROMEOS)
   // If a scan of available devices has already completed, use material-hybrid
   // if a touchscreen is present.
   if (DeviceDataManager::HasInstance() &&
       DeviceDataManager::GetInstance()->device_lists_complete()) {
     return GetTouchScreensAvailability() == TouchScreensAvailability::ENABLED
                ? MATERIAL_HYBRID
                : MATERIAL_NORMAL;
   }
@@ skipping 12 matching lines @@
     if (fd >= 0) {
       if (devinfo.Initialize(fd, path) && devinfo.HasTouchscreen()) {
         close(fd);
         return MATERIAL_HYBRID;
       }
       close(fd);
     }
   }
 #endif  // defined(USE_OZONE)
   return MATERIAL_NORMAL;
-#elif defined(OS_LINUX) || defined(OS_MACOSX)
+#elif defined(OS_LINUX) || defined(OS_MACOSX) || defined(OS_WIN)
   return MATERIAL_NORMAL;
 #else
   return NON_MATERIAL;
 #endif  // defined(OS_CHROMEOS)
 }
 
-// static
-void MaterialDesignController::Uninitialize() {
-  is_mode_initialized_ = false;
-}
-
-// static
-void MaterialDesignController::SetMode(MaterialDesignController::Mode mode) {
-  mode_ = mode;
-  is_mode_initialized_ = true;
-}
-
 }  // namespace ui