Gut ash::MaterialDesignController, and remove the about:flags entry.

chrome/browser/about_flags.cc

Index: chrome/browser/about_flags.cc
diff --git a/chrome/browser/about_flags.cc b/chrome/browser/about_flags.cc
index 2860a915a2d06a354f05478a02c296eb3c1e47ab..d3091b734686bd0f3b66a95bc3d8c3453ac6423a 100644
--- a/chrome/browser/about_flags.cc
+++ b/chrome/browser/about_flags.cc
@@ -386,18 +386,6 @@ const FeatureEntry::Choice kTopChromeMaterialDesignChoices[] = {
     switches::kTopChromeMDMaterialHybrid },
 };
 
-#if defined(USE_ASH)
-const FeatureEntry::Choice kAshMaterialDesignChoices[] = {
-    {IDS_GENERIC_EXPERIMENT_CHOICE_DEFAULT, "", ""},
-    {IDS_GENERIC_EXPERIMENT_CHOICE_DISABLED, ash::switches::kAshMaterialDesign,
-     ash::switches::kAshMaterialDesignDisabled},
-    {IDS_GENERIC_EXPERIMENT_CHOICE_ENABLED, ash::switches::kAshMaterialDesign,
-     ash::switches::kAshMaterialDesignEnabled},
-    {IDS_FLAGS_ASH_MD_EXPERIMENTAL, ash::switches::kAshMaterialDesign,
-     ash::switches::kAshMaterialDesignExperimental},
-};
-#endif  // USE_ASH
-
 #if defined(OS_CHROMEOS)
 const FeatureEntry::Choice kAshMaterialDesignInkDropAnimationSpeed[] = {
     {IDS_GENERIC_EXPERIMENT_CHOICE_DEFAULT, "", ""},
@@ -1023,8 +1011,6 @@ const FeatureEntry kFeatureEntries[] = {
         IDS_FLAGS_ASH_ENABLE_MIRRORED_SCREEN_DESCRIPTION, kOsCrOS,
         SINGLE_VALUE_TYPE(ash::switches::kAshEnableMirroredScreen),
     },
-    {"ash-md", IDS_FLAGS_ASH_MD, IDS_FLAGS_ASH_MD_DESCRIPTION, kOsCrOS,
-     MULTI_VALUE_TYPE(kAshMaterialDesignChoices)},
 #endif  // USE_ASH
 #if defined(OS_CHROMEOS)
     {"material-design-ink-drop-animation-speed",