[Mac] Website settings: Implement custom tab appearance.

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 b30e1b09bfa1d21f0cdf69d2330f5c48a29a23e0..e5ef13b990bf25eca8d21a6294a7456d239c1f0b 100644
--- a/chrome/app/theme/theme_resources.grd
+++ b/chrome/app/theme/theme_resources.grd
@@ -827,6 +827,10 @@
         <structure type="chrome_scaled_image" name="IDR_VOLUME_BUBBLE_UP_ICON" file="volume_up_icon.png" />
       </if>
       <structure type="chrome_scaled_image" name="IDR_WARNING" file="alert_small.png" />
+      <structure type="chrome_scaled_image" name="IDR_WEBSITE_SETTINGS_TAB_BACKGROUND" file="website_settings_tab_background.png" />
+      <structure type="chrome_scaled_image" name="IDR_WEBSITE_SETTINGS_TAB_CENTER" file="website_settings_tab_center.png" />
+      <structure type="chrome_scaled_image" name="IDR_WEBSITE_SETTINGS_TAB_LEFT" file="website_settings_tab_left.png" />
+      <structure type="chrome_scaled_image" name="IDR_WEBSITE_SETTINGS_TAB_RIGHT" file="website_settings_tab_right.png" />
       <if expr="not pp_ifdef('_google_chrome')">
         <structure type="chrome_scaled_image" name="IDR_WEBSTORE_ICON" file="chromium/webstore_icon.png" />
         <structure type="chrome_scaled_image" name="IDR_WEBSTORE_ICON_16" file="chromium/webstore_icon_16.png" />