[Blink] XMLTreeViewer should load resources from blink_resources.grd instead of relying upon xxd.py (Part-2)

Blink should make use of blink_resources.grd for the inline resources for displaying XML tree view.
This removes the dependency upon using xxd.py which embeds the resources as strings.

BUG=312586

Review URL: https://codereview.chromium.org/391963002

git-svn-id: svn://svn.chromium.org/blink/trunk@178522 bbb929c8-8fbe-4397-9dbb-9b2b20218538