Dark mode miscellany

No specific bugs, this is from pairing with namratakannan@

- Update background color for autofill footer
- Fix a button in the profile menu sign in UI

Change-Id: Iafdddd6d6703cbb97bc633dca9b43e232d0a9028
Reviewed-on: https://chromium-review.googlesource.com/c/1434895Reviewed-by: Elly Fong-Jones <ellyjones@chromium.org>
Commit-Queue: Leonard Grey <lgrey@chromium.org>
Cr-Commit-Position: refs/heads/master@{#625794}

chrome/browser/ui/views/profiles/profile_chooser_view.cc

@@ -1248,8 +1248,7 @@ views::View* ProfileChooserView::CreateDiceSigninView() {
 
   // Add sign out button.
   signout_button_ = views::MdTextButton::Create(
-      this, l10n_util::GetStringUTF16(IDS_SCREEN_LOCK_SIGN_OUT),
-      views::style::CONTEXT_BUTTON);
+      this, l10n_util::GetStringUTF16(IDS_SCREEN_LOCK_SIGN_OUT));
   promo_button_container->AddChildView(signout_button_);
 
   view->AddChildView(promo_button_container);

ui/native_theme/common_theme.cc

@@ -86,7 +86,7 @@ SkColor GetAuraColor(NativeTheme::ColorId color_id,
       case NativeTheme::kColorId_LinkPressed:
         return gfx::kGoogleBlue300;
       case NativeTheme::kColorId_HighlightedMenuItemBackgroundColor:
-        return gfx::kGoogleGrey700;
+        return SkColorSetRGB(0x32, 0x36, 0x39);
       case NativeTheme::kColorId_TreeBackground:
         return gfx::kGoogleGrey800;
       case NativeTheme::kColorId_TreeText: