Migrate all usages of xxd.py to blink_resources.grd and remove xxd.py - Part 1

Blink should make use of blink_resources.grd for the inline resources of inspector.
This removes the dependency upon using xxd.py which embeds these resources as strings.

Part 2: https://crrev.com/403273003
Part 3: https://crrev.com/402033002

BUG=312586

Review URL: https://codereview.chromium.org/401233003

git-svn-id: svn://svn.chromium.org/blink/trunk@178832 bbb929c8-8fbe-4397-9dbb-9b2b20218538