First try at a user management screen for the desktop

chrome/app/theme/theme_resources.grd

Index: chrome/app/theme/theme_resources.grd
diff --git a/chrome/app/theme/theme_resources.grd b/chrome/app/theme/theme_resources.grd
index 6ae96842eb91285369a4f002236955c7a3ea02ff..63fec8e9f8798446bb35e3cc7622a89760cce316 100644
--- a/chrome/app/theme/theme_resources.grd
+++ b/chrome/app/theme/theme_resources.grd
@@ -348,10 +348,16 @@
         <structure type="chrome_scaled_image" name="IDR_HOME_H" file="common/browser_home_hover.png" />
         <structure type="chrome_scaled_image" name="IDR_HOME_P" file="common/browser_home_pressed.png" />
       </if>
-      <if expr="pp_ifdef('chromeos')">
+      <if expr="not is_android and not pp_ifdef('ios')">
         <structure type="chrome_scaled_image" name="IDR_ICON_ADD_USER24" file="icon_add_user24.png" />
         <structure type="chrome_scaled_image" name="IDR_ICON_ADD_USER_WHITE" file="icon_add_user_white.png" />
         <structure type="chrome_scaled_image" name="IDR_ICON_GUEST_WHITE" file="icon_guest_white.png" />
+      </if>
+      <if expr="not is_android and not pp_ifdef('ios') and not pp_ifdef('chromeos')">
+        <!-- TODO(noms): Remove this once local profile avatars are migrated -->
+        <structure type="chrome_scaled_image" name="IDR_USER_MANAGER_DEFAULT_AVATAR" file="avatar_user_color.png" />
+      </if>
+      <if expr="pp_ifdef('chromeos')">
         <structure type="chrome_scaled_image" name="IDR_ICON_POWER24" file="icon_power24.png" />
         <structure type="chrome_scaled_image" name="IDR_ICON_POWER_WHITE" file="icon_power_white.png" />
       </if>