Add HiDPI assets for the WebUI bookmarks manager.

chrome/browser/resources/component_extension_resources.grd

Index: chrome/browser/resources/component_extension_resources.grd
diff --git a/chrome/browser/resources/component_extension_resources.grd b/chrome/browser/resources/component_extension_resources.grd
index 057c356fc692d0d16ca28e57f7c51f75cc3ea495..bb305e69c02610cf89a295c606125ccbff3b4de0 100644
--- a/chrome/browser/resources/component_extension_resources.grd
+++ b/chrome/browser/resources/component_extension_resources.grd
@@ -11,11 +11,13 @@
     <output filename="component_extension_resources.pak" type="data_package" />
   </outputs>
   <release seq="1">
+    <structures>
+      <structure name="IDR_BOOKMARK_MANAGER_MAIN" file="bookmark_manager/main.html" flattenhtml="true" allowexternalscript="true" type="chrome_html" />
+    </structures>
     <includes>
       <include name="IDR_BOOKMARK_MANAGER_BOOKMARK_MANAGER_RECENT" file="bookmark_manager/images/bookmark_manager_recent.png" type="BINDATA" />
       <include name="IDR_BOOKMARK_MANAGER_BOOKMARK_MANAGER_SEARCH" file="bookmark_manager/images/bookmark_manager_search.png" type="BINDATA" />
       <include name="IDR_BOOKMARK_MANAGER_BOOKMARK_MANAGER_SEARCH_RTL" file="bookmark_manager/images/bookmark_manager_search_rtl.png" type="BINDATA" />
-      <include name="IDR_BOOKMARK_MANAGER_MAIN" file="bookmark_manager/main.html" flattenhtml="true" allowexternalscript="true" type="BINDATA" />
       <include name="IDR_BOOKMARK_MANAGER_BOOKMARK_MAIN_JS" file="bookmark_manager/js/main.js" type="BINDATA" />
       <include name="IDR_BOOKMARK_MANAGER_BOOKMARK_BMM_LIST_JS" file="bookmark_manager/js/bmm/bookmark_list.js" type="BINDATA" />
       <include name="IDR_BOOKMARK_MANAGER_BOOKMARK_BMM_TREE_JS" file="bookmark_manager/js/bmm/bookmark_tree.js" type="BINDATA" />