[mojo] Make HTML viewer load the blink resources from the generated pak file.
Blink is about to make use of blink_resources.grd for the inline resources of user agent stylesheets.
This removes the dependency upon using make-file-arrays.py which embeds these resources as strings.
See part 1, 2 and 3.
Also the .rodata section of libblink_web (in component build mode) is reduced by ~33kb.
In this CL, the html viewer would implement the loadResource() method and use the DataPack to
load the required resources. The resources are generated from blink_resources.grd which has been
added as the deps.
Part 1: https://codereview.chromium.org/
436843004/
Part 2: https://codereview.chromium.org/
422023008
Part 3: https://codereview.chromium.org/
573553002
BUG=312586
Review URL: https://codereview.chromium.org/
827223002
Cr-Commit-Position: refs/heads/master@{#311420}