Revert of Enable whitelisting for targets other than libchrome. (patchset #8 id:40002 of https://codereview.chromium.org/2336033002/ )

Reason for revert:
Broke ninja on Linux x64:

ninja: Entering directory `out/Release'
[1/1] Regenerating ninja files
FAILED: build.ninja
/mnt/ssd/miu/chromium/src/buildtools/linux64/gn --root=/mnt/ssd/miu/chromium/src -q gen //out/Release/
ERROR at //chrome/BUILD.gn:1358:5: Undefined identifier.
    public_deps += [ ":default_apps" ]
    ^----------
See //BUILD.gn:211:7: which caused the file to be included.
      "//chrome",
      ^---------
ninja: error: rebuilding 'build.ninja': subcommand failed

Original issue's description:
> Refactor chrome resource targets into chrome_paks.gni
>
> This will allow monochrome to easily define its own set of the same
> targets with a different resource whitelist
>
> BUG=641032
>
> Committed: https://crrev.com/33312c3d3dc09f27325e74644b346123b325891e
> Cr-Commit-Position: refs/heads/master@{#418966}

TBR=brettw@chromium.org,agrieve@chromium.org
# Skipping CQ checks because original CL landed less than 1 days ago.
NOPRESUBMIT=true
NOTREECHECKS=true
NOTRY=true
BUG=641032

Review-Url: https://codereview.chromium.org/2348643002
Cr-Commit-Position: refs/heads/master@{#418992}
3 files changed