Makes MaterialDesignController initialization explicit

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/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 "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::Mode::NON_MATERIAL;
 
+// static
+void MaterialDesignController::Initialize() {
+  TRACE_EVENT0("startup", "MaterialDesignController::InitializeMode");
+  CHECK(!is_mode_initialized_);

[varkha, 2016/04/06 04:49:33]

estade@, can you please take another look? I have reworked this CL to avoid lazy
initialization of the MDC and it should have CHECKs in place to enforce it. I
think this is less brittle than what we had before where we already had to work
around obscure initialization sequence on Mac. Of course it also fixes the
original linux bug.

+#if !defined(ENABLE_TOPCHROME_MD)
+  SetMode(Mode::NON_MATERIAL);
+#else
+  const std::string switch_value =
+      base::CommandLine::ForCurrentProcess()->GetSwitchValueASCII(
+          switches::kTopChromeMD);
+
+  if (switch_value == switches::kTopChromeMDMaterial) {
+    SetMode(Mode::MATERIAL_NORMAL);
+  } else if (switch_value == switches::kTopChromeMDMaterialHybrid) {
+    SetMode(Mode::MATERIAL_HYBRID);
+  } else if (switch_value == switches::kTopChromeMDNonMaterial) {
+    SetMode(Mode::NON_MATERIAL);
+  } else {
+    if (!switch_value.empty()) {
+      LOG(ERROR) << "Invalid value='" << switch_value
+                 << "' for command line switch '" << switches::kTopChromeMD
+                 << "'.";
+    }
+    SetMode(DefaultMode());
+  }
+#endif  // !defined(ENABLE_TOPCHROME_MD)
+}
+
+// static
 MaterialDesignController::Mode MaterialDesignController::GetMode() {
-  if (!is_mode_initialized_)
-    InitializeMode();
   CHECK(is_mode_initialized_);
   return mode_;
 }
 
+// static
 bool MaterialDesignController::IsModeMaterial() {
   return GetMode() == Mode::MATERIAL_NORMAL ||
          GetMode() == Mode::MATERIAL_HYBRID;
 }
 
+// static
 MaterialDesignController::Mode MaterialDesignController::DefaultMode() {
 #if defined(OS_CHROMEOS)
   if (DeviceDataManager::HasInstance() &&
       DeviceDataManager::GetInstance()->device_lists_complete()) {
     return GetTouchScreensAvailability() == TouchScreensAvailability::ENABLED ?
         Mode::MATERIAL_HYBRID : Mode::MATERIAL_NORMAL;
   }
 
 #if defined(USE_OZONE)
   base::FileEnumerator file_enum(
@@ skipping 13 matching lines @@
   }
 #endif  // defined(USE_OZONE)
   return Mode::MATERIAL_NORMAL;
 #elif defined(OS_LINUX)
   return Mode::MATERIAL_NORMAL;
 #else
   return Mode::NON_MATERIAL;
 #endif  // defined(OS_CHROMEOS)
 }
 
-void MaterialDesignController::InitializeMode() {
-#if !defined(ENABLE_TOPCHROME_MD)
-  SetMode(Mode::NON_MATERIAL);
-#else
-  const std::string switch_value =
-      base::CommandLine::ForCurrentProcess()->GetSwitchValueASCII(
-          switches::kTopChromeMD);
-
-  if (switch_value == switches::kTopChromeMDMaterial) {
-    SetMode(Mode::MATERIAL_NORMAL);
-  } else if (switch_value == switches::kTopChromeMDMaterialHybrid) {
-    SetMode(Mode::MATERIAL_HYBRID);
-  } else if (switch_value == switches::kTopChromeMDNonMaterial) {
-    SetMode(Mode::NON_MATERIAL);
-  } else {
-    if (!switch_value.empty()) {
-      LOG(ERROR) << "Invalid value='" << switch_value
-                 << "' for command line switch '" << switches::kTopChromeMD
-                 << "'.";
-    }
-    SetMode(DefaultMode());
-  }
-#endif  // !defined(ENABLE_TOPCHROME_MD)
-}
-
+// static
 void MaterialDesignController::UninitializeMode() {
   MaterialDesignController::SetMode(
       MaterialDesignController::Mode::NON_MATERIAL);
   is_mode_initialized_ = false;
 }
 
+// static
 void MaterialDesignController::SetMode(MaterialDesignController::Mode mode) {
   mode_ = mode;
   is_mode_initialized_ = true;
 }
 
 }  // namespace ui