Get rid of all component builds specific .isolate.

The status quo was unmaintainable.  These 'component build specific .isolate
files' are superseeded by tools/isolate_driver.py which packages dynamic
libraries automatically.

The new way is much more sane and dynamic, isolate_driver.py is currently very
crude but 'does the job', the expected way to make it work is to read the .ninja
files to extract all the dynamic libraries marked as a dependency to the main
target being executed.

TBR=csharp@chromium.org
BUG=333473

Review URL: https://codereview.chromium.org/226123004

git-svn-id: https://src.chromium.org/chrome/trunk/src/url@261871 4ff67af0-8c30-449e-8e8b-ad334ec8d88c
Minor GN build cleanup.

Convert some static libraries to source sets.

Add an "icu" metalibrary that can be used by targets needing both ICU libs.

Rename some base targets to have shorter names.

BUG=
R=scottmg@chromium.org

Review URL: https://codereview.chromium.org/225093021

git-svn-id: https://src.chromium.org/chrome/trunk/src/url@262442 4ff67af0-8c30-449e-8e8b-ad334ec8d88c
We have Component::reset(), so use it.

BUG=none
TEST=none
R=brettw@chromium.org

Review URL: https://codereview.chromium.org/227483013

git-svn-id: https://src.chromium.org/chrome/trunk/src/url@262554 4ff67af0-8c30-449e-8e8b-ad334ec8d88c