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

chrome/browser/chrome_browser_main.cc

Index: chrome/browser/chrome_browser_main.cc
diff --git a/chrome/browser/chrome_browser_main.cc b/chrome/browser/chrome_browser_main.cc
index 2b0b0633d38214028d652ae62d2ac1924af98fc2..8ceaf04ad9d1543e08a462232f10f97dc24bf1d1 100644
--- a/chrome/browser/chrome_browser_main.cc
+++ b/chrome/browser/chrome_browser_main.cc
@@ -978,19 +978,6 @@ int ChromeBrowserMainParts::PreCreateThreadsImpl() {
                                         flags_ui::kAddSentinels);
   }
 #endif  // !defined(OS_CHROMEOS)
-  // The MaterialDesignController needs to look at command line flags, which
-  // are not available until this point. Now that they are, proceed with
-  // initializing the MaterialDesignController.
-  ui::MaterialDesignController::Initialize();
-#if defined(OS_CHROMEOS)
-  ash::MaterialDesignController::Initialize();
-#endif  // !defined(OS_CHROMEOS)
-
-#if defined(OS_MACOSX)
-  // Material Design resource packs can be loaded now that command line flags
-  // are set. See https://crbug.com/585290 .
-  ui::ResourceBundle::GetSharedInstance().LoadMaterialDesignResources();
-#endif
 
 #if defined(OS_WIN)
   // This is needed to enable ETW exporting when requested in about:flags.
@@ -1012,50 +999,6 @@ int ChromeBrowserMainParts::PreCreateThreadsImpl() {
   crash_keys::SetCrashKeysFromCommandLine(
       *base::CommandLine::ForCurrentProcess());
 
-  // Mac starts it earlier in |PreMainMessageLoopStart()| (because it is
-  // needed when loading the MainMenu.nib and the language doesn't depend on
-  // anything since it comes from Cocoa.
-#if defined(OS_MACOSX)
-  std::string locale =
-      parameters().ui_task ? "en-US" : l10n_util::GetLocaleOverride();
-  browser_process_->SetApplicationLocale(locale);
-#else
-  const std::string locale =
-      local_state_->GetString(prefs::kApplicationLocale);
-
-  // On a POSIX OS other than ChromeOS, the parameter that is passed to the
-  // method InitSharedInstance is ignored.
-
-  TRACE_EVENT_BEGIN0("startup",
-      "ChromeBrowserMainParts::PreCreateThreadsImpl:InitResourceBundle");
-  const std::string loaded_locale =
-      ui::ResourceBundle::InitSharedInstanceWithLocale(
-          locale, NULL, ui::ResourceBundle::LOAD_COMMON_RESOURCES);
-  TRACE_EVENT_END0("startup",
-      "ChromeBrowserMainParts::PreCreateThreadsImpl:InitResourceBundle");
-
-  if (loaded_locale.empty() &&
-      !parsed_command_line().HasSwitch(switches::kNoErrorDialogs)) {
-    ShowMissingLocaleMessageBox();
-    return chrome::RESULT_CODE_MISSING_DATA;
-  }
-  CHECK(!loaded_locale.empty()) << "Locale could not be found for " << locale;
-  browser_process_->SetApplicationLocale(loaded_locale);
-
-  {
-    TRACE_EVENT0("startup",
-        "ChromeBrowserMainParts::PreCreateThreadsImpl:AddDataPack");
-    base::FilePath resources_pack_path;
-    PathService::Get(chrome::FILE_RESOURCES_PACK, &resources_pack_path);
-#if defined(OS_ANDROID)
-    ui::LoadMainAndroidPackFile("assets/resources.pak", resources_pack_path);
-#else
-    ResourceBundle::GetSharedInstance().AddDataPackFromPath(
-        resources_pack_path, ui::SCALE_FACTOR_NONE);
-#endif  // defined(OS_ANDROID)
-  }
-#endif  // defined(OS_MACOSX)
-
   // Android does first run in Java instead of native.
   // Chrome OS has its own out-of-box-experience code.
 #if !defined(OS_ANDROID) && !defined(OS_CHROMEOS)
@@ -1150,6 +1093,70 @@ int ChromeBrowserMainParts::PreCreateThreadsImpl() {
   // IOThread's initialization which happens in BrowserProcess:PreCreateThreads.
   SetupMetricsAndFieldTrials();
 
+  const version_info::Channel channel = chrome::GetChannel();
+  ui::MaterialDesignController::SetWindowsShouldDefaultToMaterial(
+      (channel == version_info::Channel::UNKNOWN) ||
+      (channel == version_info::Channel::CANARY) ||
+      (channel == version_info::Channel::DEV));

[varkha, 2016/05/06 14:58:22]

Would it make sense to conditionally compile this as well as
ui::MaterialDesignController windows bits only when OS_WIN is defined?

[Peter Kasting, 2016/05/13 06:36:45]

Sure.  It would be harmless to do the other way, but why run code you don't need
to elsewhere.

I elected not to #ifdef all the related bits in material_design_controller.* in
the interest of fewer ifdefs and thus hopefully a little more readability.  This
basically just turns into an unused function/member on other platforms.  I could
be convinced to ifdef these as well if you feel strongly, but it was two more
sets of ifdefs in each of the .h and .cc file, compared with just one total
additional ifdef here.

+
+  // The MaterialDesignController needs to look at command line flags and field
+  // trials, which are not available until this point. Now that they are,
+  // proceed with initializing the MaterialDesignController.
+  ui::MaterialDesignController::Initialize();
+#if defined(OS_CHROMEOS)
+  ash::MaterialDesignController::Initialize();
+#endif  // !defined(OS_CHROMEOS)
+
+#if defined(OS_MACOSX)
+  // Material Design resource packs can be loaded now that command line flags
+  // are set. See https://crbug.com/585290 .
+  ui::ResourceBundle::GetSharedInstance().LoadMaterialDesignResources();
+#endif
+
+  // Mac starts it earlier in |PreMainMessageLoopStart()| (because it is
+  // needed when loading the MainMenu.nib and the language doesn't depend on
+  // anything since it comes from Cocoa.
+#if defined(OS_MACOSX)
+  std::string locale =
+      parameters().ui_task ? "en-US" : l10n_util::GetLocaleOverride();
+  browser_process_->SetApplicationLocale(locale);
+#else
+  const std::string locale =
+      local_state_->GetString(prefs::kApplicationLocale);
+
+  // On a POSIX OS other than ChromeOS, the parameter that is passed to the
+  // method InitSharedInstance is ignored.
+
+  TRACE_EVENT_BEGIN0("startup",
+      "ChromeBrowserMainParts::PreCreateThreadsImpl:InitResourceBundle");
+  const std::string loaded_locale =
+      ui::ResourceBundle::InitSharedInstanceWithLocale(
+          locale, NULL, ui::ResourceBundle::LOAD_COMMON_RESOURCES);
+  TRACE_EVENT_END0("startup",
+      "ChromeBrowserMainParts::PreCreateThreadsImpl:InitResourceBundle");
+
+  if (loaded_locale.empty() &&
+      !parsed_command_line().HasSwitch(switches::kNoErrorDialogs)) {
+    ShowMissingLocaleMessageBox();
+    return chrome::RESULT_CODE_MISSING_DATA;
+  }
+  CHECK(!loaded_locale.empty()) << "Locale could not be found for " << locale;
+  browser_process_->SetApplicationLocale(loaded_locale);
+
+  {
+    TRACE_EVENT0("startup",
+        "ChromeBrowserMainParts::PreCreateThreadsImpl:AddDataPack");
+    base::FilePath resources_pack_path;
+    PathService::Get(chrome::FILE_RESOURCES_PACK, &resources_pack_path);
+#if defined(OS_ANDROID)
+    ui::LoadMainAndroidPackFile("assets/resources.pak", resources_pack_path);
+#else
+    ResourceBundle::GetSharedInstance().AddDataPackFromPath(
+        resources_pack_path, ui::SCALE_FACTOR_NONE);
+#endif  // defined(OS_ANDROID)
+  }
+#endif  // defined(OS_MACOSX)
+
   // ChromeOS needs ResourceBundle::InitSharedInstance to be called before this.
   browser_process_->PreCreateThreads();