[MD Bookmarks] Persist collapsed folders between page loads.

chrome/browser/browser_resources.grd

Index: chrome/browser/browser_resources.grd
diff --git a/chrome/browser/browser_resources.grd b/chrome/browser/browser_resources.grd
index 03be53e4d535e577beb3a02bf8b1a6ec1a5f045c..829a6eea9097bba1d312bca03c9ddd3f6f80fc00 100644
--- a/chrome/browser/browser_resources.grd
+++ b/chrome/browser/browser_resources.grd
@@ -264,6 +264,8 @@
         <include name="IDR_MD_BOOKMARKS_APP_HTML" file="resources\md_bookmarks\app.html" type="BINDATA" />
         <include name="IDR_MD_BOOKMARKS_APP_JS" file="resources\md_bookmarks\app.js" type="BINDATA" />
         <include name="IDR_MD_BOOKMARKS_BOOKMARKS_HTML" file="resources\md_bookmarks\bookmarks.html" type="BINDATA" />
+        <include name="IDR_MD_BOOKMARKS_CONSTANTS_HTML" file="resources\md_bookmarks\constants.html" type="BINDATA" />
+        <include name="IDR_MD_BOOKMARKS_CONSTANTS_JS" file="resources\md_bookmarks\constants.js" type="BINDATA" />
         <include name="IDR_MD_BOOKMARKS_DND_MANAGER_HTML" file="resources\md_bookmarks\dnd_manager.html" type="BINDATA" />
         <include name="IDR_MD_BOOKMARKS_DND_MANAGER_JS" file="resources\md_bookmarks\dnd_manager.js" type="BINDATA" />
         <include name="IDR_MD_BOOKMARKS_EDIT_DIALOG_HTML" file="resources\md_bookmarks\edit_dialog.html" type="BINDATA" />