Makes MaterialDesignController initialization explicit

ui/base/material_design/material_design_controller.cc

Index: ui/base/material_design/material_design_controller.cc
diff --git a/ui/base/material_design/material_design_controller.cc b/ui/base/material_design/material_design_controller.cc
index 411f553a8ba2176680caf3caebaad04334e26c84..3c9cdb1a129d409ee354afe00b5988ad9b7db913 100644
--- a/ui/base/material_design/material_design_controller.cc
+++ b/ui/base/material_design/material_design_controller.cc
@@ -6,6 +6,7 @@
 
 #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"
 
@@ -29,18 +30,47 @@ 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() &&
@@ -74,37 +104,14 @@ MaterialDesignController::Mode MaterialDesignController::DefaultMode() {
 #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;